Citations or journal quality: which is rewarded more in the academic labor market?
Gibson, John ; Anderson, David L. ; Tressler, John 等
Citations or journal quality: which is rewarded more in the academic labor market?
1. INTRODUCTION
The evaluation of research quality is important for funding
agencies, publishers, and academic departments that make labor market
decisions about hiring, promotion, and tenure. The rise in
performance-based university research funding systems (Hicks 2012) gives
one impetus for systematically evaluating research quality. For
individual academics, the expected or revealed quality of their research
has always had profound impacts on careers, as noted by Liebowitz and
Palmer (1984, 77) in one of the seminal studies of economics journal
rankings:
Where articles are published can affect one's
promotion, tenure, and salary at one's present job; it
can also affect one's brand name and the ability to
change jobs.
Notably, it is where the article is published that the quotation
suggests has an effect. While the improved coverage, timeliness, and
ease of use of citations databases are aiding direct evaluation of
individual research outputs (Hamermesh 2017), using the journal where
something published as a proxy for the quality of the research remains
the basis for many assessments of economics departments and of
economists (e.g., Coupe 2003; Macri and Sinha 2006). (1)
There are several arguments for relying more on citations. The
prestige of the journal publishing an article should become less
informative over time, since articles are accepted based on their
predicted likelihood of having an impact, while citation-based measures
of actual impact become available as time passes. Thus, Sgroi and Oswald
(2013) show how citations give new information, in a Bayesian sense, and
as time passes the weight on this information should rise while the
weight on the prestige of the journal should fall toward zero. Also,
citations may be less affected by nepotism; according to Liebowitz
(2013, 1):
Because a journal's decision depends on the opinion
of only an editor and a few referees chosen by the
editor, there is a great deal of latitude for gratuitous
decisions. By way of contrast, the number of citations
that a paper receives is determined by the entire
academy, likely reducing the influence of gratuitous
behavior. (2)
Yet there is little comprehensive evidence on the role of citations
compared with that of journals, either in research assessment exercises
or in labor market decisions made by academic departments. Exercises
like the Research Excellence Framework (REF) in the United Kingdom may
ask panelists to ignore journal rankings and to treat each article on
its merits (where those merits may include citations) but reviewers will
be aware of rankings and ex post one can find which rankings mimic peer
evaluations (Anderson, Smart, and Tressler 2013). For labor market
decisions, there is some direct evidence from small surveys. For
example, Liebowitz (2014) finds that only 9 out of 47 economics
departments give citations equal or more weight than that given to the
rank of the publishing journal, when evaluating Associate Professors
seeking promotion to full Professor. Amongst 43 departments surveyed by
Hamermesh and Pfann (2012), all used data on recently accepted or
published journal articles when considering annual merit/salary review
requests, but only eight requested similar data on recent citations.
While regression studies of economist salaries do find significant
effects of citations, these studies often have a different focus. (3)
Moreover, most of these studies lack comprehensive controls for journal
quality. For example, Hamermesh (2017) reviews ten studies of economist
salaries that have citations as explanatory variables and just two of
these use journal quality weights. Citations and journal quality are
highly correlated so using weak (or no) journal quality measures may
cause the estimated effects of citations to be overstated.
In this paper, we comprehensively compare effects of citations and
journals on academic salary. We relate salary of tenured University of
California (UC) economists to their lifetime publications of 5,500
articles in almost 700 different academic journals, and the 140,000
citations to these articles. (4) For research-intensive universities,
salary should vary with perceived research quality. The UC is the
largest research-intensive public university system in the United
States, so provides external validity, and California has a high-quality
public salary database. We build on the seminal contribution of Ellison
(2013) in studying how the academic labor market uses citation
data--while he compares citation indices, we examine a broader issue of
citations versus journals. While citations and journals are used in
prior studies of academic salary, our approach is more comprehensive. We
use nine different journal assessment schemes to provide quality weights
for calculating size-, coauthor-, and quality-adjusted lifetime output
in journals. We also compare highly ranked and less highly ranked
departments, and we search for the optimally weighted combination of
citations and journals for articles of different vintages.
The results show citations hardly affect salary, especially in
top-ranked UC departments where citations have impacts less than
one-tenth those of journals. In lower ranked departments, and when
journal quality is less comprehensively controlled for, the estimated
effects of citations increase. For example, using article counts rather
than quality-weighted journal output causes estimated effects of
citations to triple or more (depending on specification). Our results
contrast with a recent study by Hilmer, Ransom, and Hilmer (2015),
hereafter referred to as HRH, who used a larger sample with lower ranked
schools, and found that controlling for journals (with article counts in
tiers of journal quality) did not affect the magnitude of estimated
citation effects. If the HRH specification is applied to the UC data, in
conjunction with our approach of using quality-weighted journal output,
the quality-weighted approach dominates. In particular, the journal
tiers variables are never statistically significant while
quality-weighted journal output remains significant in almost all salary
equations.
To further advance the argument that how one controls for journal
quality may alter the apparent effect of citations, we use the HRH
sample and supplement their salary equations with our quality-weighted
measures of journal output. For assessment schemes that most heavily
discount lower ranked journals, the estimated effects of citations on
salary are up to 40% larger if the HRH journal tiers approach to
measuring journal output is used rather than using our approach of
calculating quality-weighted journal output. The sensitivity of
estimated citation effects with respect to the different ways of
controlling for journals is much more apparent for the top schools in
the HRH sample. (5) Specifically, for top schools, the apparent effect
of citations on salary is up to 60% larger if the HRH journal tiers are
used to measure journal output compared to if our quality-weighted
journal output measures are used.
Our results suggest that salary determination differs by school
rank, which has previously been discussed by Hamermesh and Pfann (2012)
and Liebowitz (2014). At the top UC schools, quality-adjusted journal
output matters to salary while citations hardly matter, while in the
lower ranked UC schools it is a mix of both citations and journals that
matters. At the top schools in the HRH sample, both matter with journals
slightly more important than citations. In contrast, salary setting for
the bottom schools in the HRH sample seems to be more of a counting
exercise, with total counts of articles (with no quality tiers) and
total counts of citations affecting salary but no premium for journal
quality. These results supportive an argument made by Liebowitz (2014)
that faculty at lower ranked schools may rely on easily available
proxies, such as counts of articles or of citations, rather than making
their own determination based on reading the articles when they have to
evaluate a research record in order to make a labor market decision. (6)
The rest of the paper is structured as follows: Section II reviews
previous studies, noting that the growing literature on journal quality
weights is largely ignored in studies of academic salary for economists,
where simple counts of articles in journal quality tiers are typically
used. Section III describes the UC data and the nine different sets of
journal quality weights, which are used in the Section IV analyses that
compare salary impacts of citations with those of journals. In Section
V, we reconcile our results with other recent studies, showing that two
patterns from the UC results--that effects of citations on salary are
higher in lower ranked departments, and when journal quality is less
comprehensively measured--also hold in the larger sample used by HRH
(2015). Section VI has the conclusions.
II. PREVIOUS LITERATURE
The relationship between academic salary for economists and various
metrics of research output and quality has been studied since the 1970s.
This literature often uses classifications of journals in broadly
defined excellence tiers, and citation-based metrics, to represent
research quality. In the same era, literature on formal journal
assessment schemes developed from the seminal work of Liebowitz and
Palmer (1984), who rank economics journals using impact-adjusted
citations. (7) An important feature of these journal assessment schemes
is that they provide quality weights that can be used to convert
articles in different journals into a constant quality output measure.
For example, Economic Inquiry gets a weight of 8.70 (the highest is 100)
in the impact-adjusted citations rankings of Liebowitz and Palmer
(1984). These weights are informative because even if there was
consensus on ordinal ranks for journals (which there is not, beyond the
top-5) the weights for comparing journals may not be agreed upon. Thus,
the Combes and Linnemer (2010) ranking has two weights for each journal,
from differentially discounting lower ranked journals (for Economic
Inquiry these weights are 24 and 6, where 100 is for the top journal).
If journals are simply grouped by rank with no accounting for
weights--as is typical in academic labor market studies--potentially
relevant information (that correlates with citations) is ignored.
Hamermesh, Johnson, and Weisbrod (1982) were the first to use
citations to represent research quality in an academic economist salary
model. They argued that "... one scholar's productivity should
be measured by the sum of direct and indirect influences on other
producers as well as by direct contributions (publications)" (473).
Using 5 years of citations data from the Social Science Citation Index
for 148 professors of economics from seven large public universities,
they fitted a model in which citations were the only measure of research
output or quality. For six of the universities, citations had a positive
impact on salaries, and explained from 6.5% to 27.3% of salary
variation. For the two universities for which counts of publications
were also available to represent research output, citations continued to
be significant determinant of salaries and explained a similar
proportion of salary variation as that explained by publications.
Effects of seniority are a focus for several studies that exemplify
how publications data and citations are used in salary models. (8)
Ransom (1993) found that salaries exhibited negative returns to
seniority in faculty surveys across many disciplines, attributing this
to monopsonistic discrimination. Controlling for research productivity
with publication counts did not alter this pattern. In contrast, Moore,
Newman, and Turnbull (1998) found that the negative seniority effect
disappeared in a study of 142 economists at nine state universities, as
more comprehensive measures of research productivity were added. Once
counts of articles in two tiers of journals, and citations (as a count
and interacted with the article counts), were added to the salary
equations, the coefficient on the seniority variable became
insignificant. Although comparing the impact of journal quality with
that of citations was not the focus of Moore, Newman, and Turnbull
(1998), a feature of their approach persists in much of the subsequent
literature, which is to use counts of articles in journal tiers as a
measure of research quality. (9) Their top tier of ten journals included
Economica, yet this journal ranked just 28th in the Liebowitz and Palmer
(1984) rankings. Thus, two problems for the tiers approach are that
journals with higher quality weights are often excluded from the top
tiers, and within-tier variation in quality weights is ignored; for
example, Economica had a weight of just 5.9% of that of the top journal
(the American Economic Review [AER]) in the same tier.
Similar issues of poorly specified tiers and ignoring within-tier
variation affect two later studies of seniority by Bratsberg, Ragan, and
Warren (2003, 2010). (10) Bratsberg, Ragan, and Warren (2003) use two
journal tiers; the top one is the same as what Moore, Newman, and
Turnbull (1998) use and the second tier consists of the rest of the 36
journals used by Scott and Mitias (1996). Bratsberg, Ragan, and Warren
(2010) further divide other journals outside these two tiers into a
further two tiers. The within-tier heterogeneity can be seen with two
weighting schemes toward opposite ends of the scale of discounting lower
ranked journals: the Combes and Linnemer (2010) medium-convexity CLm
scheme based on citation measures and the Kalaitzidakis, Mamuneas, and
Stengos (2010) KMS scheme based on impact-adjusted citations. With the
CLm scheme, journals in the Bratsberg et al. top tier have quality
weights that vary between 100 for the Quarterly Journal of Economics
(QJE) to 27.2 for Economica. In the KMS scheme they vary between 100 for
the AER and 2.2 for Economica. For their second tier, the CLm weights
range from 80.6 (Journal of Financial Economics) to 13.6 (Journal of
Regional Science). Under the KMS scheme, several journals in this tier
are not ranked (so implicitly get a weight of zero), and weights of the
ranked journals range from 27.8 (Journal of Monetary Economics) to 0.4
(Journal of Regional Science). Irrespective of views about appropriate
rates for down-weighting lower ranked journals, it is clear that a lot
of information is lost through the treatment of all articles in a
journal tier as representing the same research quality.
In contrast to the tiers approach, Sauer (1988) is a rare example
of using journal weights to study academic labor markets. He uses
Liebowitz and Palmer (1984) weights to quality-adjust size-standardized
and coauthor-adjusted journal pages, in a salary model for 140
economists from seven "top 40" schools. The degree of
prorating for coauthorship and the extent to which salary varies with
the original journal weights compared with an all-journals-are-equal
scheme is determined from the data. (11) The results show that citations
and quality-adjusted journal pages both affect salary although these two
impacts are not compared. Relatedly, Gibson, Anderson, and Tressler
(2014) use labor market data to sift between nine commonly used journal
assessment schemes and find that more inclusive schemes, where weights
do not decline sharply with the rank of the journal (such as the CLm
scheme), have the greatest congruence with salaries of UC economists.
Ellison (2013) also uses labor market data to sift between
competing metrics, for variants of the citation-based h-index of Hirsch
(2005). Ellison develops a class of generalized h-like measures,
[h.sub.(a,b)] for the number h such that one has at least h papers with
a[h.sup.b] citations. With the rank of the employing department as the
labor market indicator, using Google Scholar citations Ellison finds a
wide range of values of the parameters a and b outperform h =
[h.sub.(1,1)] and suggests [h.sub.(15,2)] as a metric for younger
scholars and [h.sub.(5,2)] for seasoned academics. These generalized
measures concentrate attention on a few, highly cited, publications and
this may be a by-product of using Google Scholar, which includes a wider
range of research outputs, and far higher citations counts than those
from Web of Science (WoS). (12) Perhaps for this reason, HRH (2015) find
contrary evidence to Ellison; using WoS citations the original h-index
outperforms the [h.sub.(15,2)] index, in explaining salary in their
sample of 1,009 economists at 53 public universities.
While HRH (2015) experiment with different citations metrics, in
also using a quadratic in log citations plus one, they just use a
conventional journal tiers approach to measuring the quality and
quantity of publications. Specifically, counts of items published in an
"elite" tier of top-5 journals (but using Review of Economics
and Statistics rather than Review of Economic Studies, which is
typically thought of as the fifth of the top-5), and an
"excellent" tier of the other 31 journals in Scott and Mitias
(1996) are used, along with counts of all other items recorded in WoS.13
Two issues with the tiers approach, of higher ranked journals being
omitted from tiers and of ignoring within-tier variation, also apply to
this study and may explain why adding these tier counts hardly changed
citations coefficients in the HRH salary models. Journals in the HRH
"excellent" group occupy places between 5th and 155th place in
the CLm rankings, with an average rank of 45th rather than 21st that
would be expected (they should be 6th to 36th placed, since the top-5
are in the "elite" group). In terms of within-tier variation,
the "excellent" group has journals whose CLm quality weight
ranges from just 13.5% of the weight for the QJE all the way up to 81 %
of the QJE and yet these journals are all treated as equally excellent.
Many studies include citations and some measure of journal output
in their salary models but impacts of the two types of variables are not
compared. One exception is Hamermesh and Pfann (2012); they report that
going from the 25th to the 75th percentile of total citations raises
salary by 33% for their sample of 564 economists, while the same
percentile increase in the number of articles raises salary by only 6%.
This comparison does not control for journal quality, which is highly
correlated with citations, so the absence of journal quality measures
may cause citation impacts to be overstated. In general, article counts
may not be the best summary measure of journal output, and a
head-to-head comparison shows that counts of articles explain less
variation in salary than is explained by size-, coauthor- and
quality-adjusted pages (Gibson 2014). Thus the question of what a
comparison of citations versus journals might reveal when a more
complete representation of journal quality is used remains open.
III. DATA DESCRIPTION
The sample is all Professors and Associate Professors in economics
departments of UC campuses, except adjuncts, affiliates, part-timers,
and anyone with primarily teaching or administrative roles. This group
of n = 167 is a subset of the sample of Gibson, Anderson, and Tressler
(2014), excluding Assistant Professors, who typically have few
citations. The findings are, thus, most germane for comparing impacts of
citations and journals on salary for seasoned scholars. The dependent
variable is the (log of) base salary for the 2010 academic year. Control
variables are a quadratic in experience, a gender dummy, fixed effects
for each UC campus, the proportion of lifetime articles that were in
journals not covered by WoS at the time of publication, and a dummy for
individuals not on a standard 9-month academic year and pay scale. (14)
The citations are to the lifetime articles published by these 167
tenured professors up to the end of 2010. The articles are mainly from
WoS, although it was often easier to find them by first checking
EconLit, RePEc, and curriculum vitae, especially for people with common
names. Moreover, some economics journals (defined by the union of
EconLit and RePEc) are only listed in IPOS' in more recent years so
the other databases are needed for finding these articles. (15) In
total, there were about 5,500 articles in almost 700 different academic
journals. The 140,000 citations to these articles are from the WoS,
which is the most established citations database, with stricter coverage
than Google Scholar which includes citations to and from various
unpublished works. For articles in journals not covered by WoS at the
time of publication, their citations appear to be zero even if citations
show up in other databases. Hamermesh (2017) reports a rough conversion
rate of 17 WoS citations for every 100 in Google Scholar. We did not use
this to impute these missing citations since the conversion factor is
calculated from junior scholars and the lack of WoS coverage is more of
a problem for senior academics with older articles. Instead, our salary
models include an indicator for the proportion of articles published by
each economist in journals that were not in WoS at the time, so as to
account for this potential undercoverage.
In order to compare citations with a comprehensive measure of
quality-adjusted journal output we need weights to convert output to a
constant quality level (equal to the highest ranked journal, which is
the QJE for most schemes). A wide range of journal assessment schemes
have been proposed by economists, with no consensus on which is best.
Thus, we use nine different schemes to ensure that results do not depend
on the particular weights used. (16) Journal assessment schemes differ
in terms of coverage, and aggressiveness (or convexity), which is the
rate weights decline for lower ranked journals. In our application,
coverage can be indicated by the percentage of lifetime articles by UC
economists that receive zero weight. The elasticity of weights with
respect to rank provides a measure of aggressiveness. The full
descriptions for each scheme are in Gibson, Anderson, and Tressler
(2014), with their brief details as follows:
* Mason, Steagall, and Fabritius: [MSF] reputational weights for
142 journals from a survey of economics department chairs. This is the
least aggressive (a rank elasticity of -0.22) but has low coverage (30%
of articles by UC economists are not counted).
* Coomes and Linnemer: [CLm, CLh] is the most comprehensive,
covering 1,168 journals by using a Google Scholar /2-index to
extrapolate from citations for EconLit journals to all journals (thus,
just 11% of articles by UC economists are not counted). Two different
rates for down-weighting lower ranked journals are used; a medium
variant (CLm) with a rank elasticity of -0.67, and a high variant (CLh)
with a rank elasticity of -1.35.
* RePEc is an impact factor from unweighted citations, covering 984
journals (when we collected the data in May 2012), and is the fourth
least aggressive of the nine schemes with a rank elasticity of -1.17 and
a coverage rate of 87%.
* Coupe is an average of 2-year impact factors for 1994-2000 from
the Journal Citation Reports for 273 economics journals; this is the
third least aggressive of the nine schemes with a rank elasticity of
-0.78 and a coverage rate of 78%.
* Kodrzycki and Yu [2006; K&Y_all, K&Y_econ] is an
"eigenfactor" approach where a journal is deemed influential
if cited often by other influential journals. Subdiscipline citing
intensity is adjusted for, with cites from all social science journals
[K&Y_all] and just from economics [K&Y_econ], The rank
elasticities are -1.48 and -1.53, and 74% of articles by UC economists
are covered by the ranked journals.
* Kalaitzidakis, Mamuneas, and Stengos: [KMS] is an eigenfactor
approach, using the average of citations from 2003-2008 to articles
published in the previous 10 years. This is the second most aggressive
scheme, with a rank elasticity of -1.74. It has the second lowest
coverage rate, with 30% of articles by UC economists having zero weight.
* Laband and Piette: [LP] is an eigenfactor approach using
citations to 130 economics journals over 1985-1989 by articles published
in 1990. It has the lowest coverage, with 36% of articles by UC
economists given zero weight, and the largest rank elasticity (-1.92).
Appendix Table A1 has normalized weights under each of these nine
schemes, for each journal in the "elite" and
"excellent" tiers of HRH, and also mean weights and ranks, and
the highest and lowest rank. The issue of poorly specified tiers is
shown by the six journals in the "excellent" tier that have a
higher mean rank than the bottom journal of the "elite" group.
The issue of within-tier variation is seen in mean weights that range
from 0.37 to 0.80 for the "elite" journals and 0.12 to 0.63
for the "excellent" journals. Moving across the columns of the
table from the least aggressive to most aggressive schemes shows the
variation in these schemes, which should pick up different aspects of
the representation of research quality. For example, under the MSF
scheme, the range in the top two tiers of HRH journals is just from 1.00
to 0.64 so it is close to treating all journals as equal, whereas KMS is
one of the most aggressive schemes with a range of weights from 1.00 to
0.01 (and omits five journals whose implicit weight is zero).
Using each set of weights (including zero for unranked journals),
the pages for every article published by sample members are multiplied
by the quality weight, adjusting for the number of authors and
standardizing to the size of a typical page in the AER (17):
Article Pages X Size Correction
X (1 /number of authors)
X Journal Assessment Weight.
In comparison to the journal tiers approach, we have more granular
data on the quality of journal output for each economist. Our
quality-weighted output approach should deal with issues of poorly
specified tiers and within-tier variation, and also captures variation
in the size of articles.
The definitions and summary statistics for our various citations
metrics, our measures of lifetime (to 2010) quality-adjusted journal
output, and the control variables are in Table 1. The lifetime journal
output ranges from an average of 44 pages using LP journal weights
(which are the most discriminating) to 174 pages using MSF weights (the
least discriminating), from an average of 33 articles published in the
career to date. The total citations to these articles for each economist
average just over 800, with a maximum of over 15,000, while the most
highly cited article per economist averages 200 citations. The average
h-index for these academics is just over 11, while the generalized
h-index proposed by Ellison (2013) averages 2.5. We use the
[h.sub.(5.2)] variant because Ellison estimates a = 5 and b = 2 for a
sample from top-50 departments who average 22 years post-PhD, which is
same level of experience as the current sample.
IV. RESULTS
The basic academic salary equations are reported in Table 2 and
these explain about two-thirds of the variation in log salary for these
economists. All nine regressions show a highly significant (at p <
.01 level) positive effect on salary of quality-adjusted journal output.
The journals and citations variables are standardized throughout, to
facilitate comparisons, so the coefficients in Table 2 show that a
standard deviation increase in quality-adjusted journal output raises
salary by 10%-15%. The effect is highest when quality-adjusted output is
based on less convex journal weighting schemes like MSF and CLm, which
tend to give the best-fitting salary equations.18
In contrast to the always significant effect of quality-adjusted
journal output, citations are statistically significant in only three of
nine salary regressions (at just a 10% level for two). Also, citations
are significant in some of the worst-fitting models (with [R.sup.2]
values from 0.639 to 0.655, compared to 0.684 for the best-fitting
model) that have smaller journal effects. Citations and quality-adjusted
journal output correlate closely (with coefficients of 0.56 to 0.66), so
if poorer-fitting journal weights like KMS are used, estimated effects
of citations tend to strengthen. A clear demonstration that how one
controls for journal quality alters estimated effects of citations comes
from a model with no variables for journals; in this model, the
citations coefficient jumps from an average of 0.018 in Table 2 to 0.068
and becomes highly significant (t = 3.03).
This model without journals variables is not reported in Table 2,
but it lies behind the other results in Table 2, that come from
econometric "horse races" between models of salary that either
use quality-adjusted journal output or citations (with control variables
common to the two sets of models). The last row of Table 2 shows that
Vuong (1989) non-nested tests significantly favor the journals model in
all nine iterations. These tests do not presume that either competing
model is "true," and instead determine which has
verisimilitude (that is, is closer to the truth). Thus, we infer from
the results in Table 2 that a model putting weight on quality-adjusted
journal articles rather than on citations to those articles is closer to
the true model of departmental and university decision-making that
produces the faculty salaries that we observe.
In Table 3 we report the results of six sensitivity analyses that
are designed to expand upon the comparisons between quality-adjusted
journals and citations. The first analysis adds an extra covariate--the
count of articles ever published by each academic. Citations are higher
for academics who publish more articles, conditional upon their total
number of coauthor-, size-, and quality-adjusted pages (Gibson 2014).
Thus in Table 2, the citation counts may act as a proxy for an excluded
relevant variable--the total number of articles. Indeed, if this count
is put in the model, citations become statistically insignificant in all
nine salary equations (Panel A of Table 3) while quality-adjusted
journal output stays highly significant (p < .01) in all nine. (19)
The next two sensitivity analyses change the specification of the
citations variables. In Panel B, the logarithm of citations plus one is
used, following the transformation used by HRH (2015). This difference
in functional form does not appear to matter, with citations remaining
statistically insignificant in all nine models while quality-adjusted
journal output stays highly significant in all nine. In Panel C, the
citations are divided by the number of authors on each paper, whereas
the other analyses do not prorate citations in common with most prior
studies. If prorated citations are used, the effect of quality-adjusted
journals on salary is slightly stronger, with an average coefficient of
0.095 versus 0.091 in Panel A, while the effect of citations gets even
smaller and remains statistically insignificant in all nine salary
equations.
The sensitivity analyses in Panels D and E allow for the fact that
citations may vary over fields, with theorists likely to get fewer
citations than applied economists. If a dummy variable for the Journal
of Economic Literature (JEL) letter category that each economist most
frequently publishes in is added to the model the effect of journal
output is slightly increased while citation effects are decreased and
remain statistically insignificant in all nine equations. Along the same
lines, if a diversity index is calculated, based on the spread of
articles across 137 2-digit JEL categories, the small, positive, effect
on salary of contributing to more fields is apparent. The inclusion of
the diversity index brings a slight reduction in magnitude of the
journals effect, from an average of 0.091 in Panel A to 0.086 in Panel
E, but otherwise does not change the statistical significance of
journals and the insignificance of citations.
The final sensitivity analysis in Table 3 shows what happens when
campus fixed effects are excluded from the regressions. These fixed
effects are meant to capture cost-of-living and other amenity
differences between campuses but unobservable productivity that is
negatively correlated with citations and publications may also be picked
up. (20) When these fixed effects are dropped, the impact of
quality-adjusted journals is almost doubled, going from an average
effect of 0.091 to 0.173, while the impact of citations becomes smaller,
and is even negative and statistically significant with LP weights.
Considering all of these sensitivity analyses together, it appears to be
a robust finding that for UC economists their salary depends on
quality-adjusted journal output but hardly at all on citations.
The results in Table 4 exploit variation amongst the nine campuses
of the UC system that has economics departments. The top four schools
are Berkeley, UCLA, San Diego, and Davis, and salary equations just for
these four are in Panel A, with results for the other, lower ranked,
departments in Panel B. Tests for differences in coefficients between
the two subsamples are in Panel C. In the top-ranked departments,
quality-adjusted journal articles matter to salary while citations do
not, while in the lower ranked departments both are significant and have
effects of similar magnitude. Specifically, a standard deviation
increase in quality-adjusted journal output is always statistically
significant in the top four departments and has an salary impact that
ranges from 9% to 16%, with an average of 13%, while citations impact
range from -1% to 3%, average 1%, and are (weakly) significant in just
one equation. Comparing the two indicators of research productivity, for
top departments there is a 12:1 ratio for journals over citations.
In contrast, the lower ranked departments have effects of citations
and journals that are roughly equal, with average standard deviation
impacts of 0.08 for journals and 0.09 for citations. Moreover, citations
are statistically significant in all nine salary equations for the lower
ranked departments, yet were insignificant in eight equations for the
top departments. The tests of the interaction effects show that
differences in salary equations between the two subsamples are driven by
citations; journals coefficients are higher in the top departments but
the difference is statistically significant only with RePEc weights
while differences in the citations coefficients are significant in all
nine equations. The result that citations matter more in lower ranked
departments is consistent with the argument made by Liebowitz (2014)
that faculty in these types of departments may be less likely to read
articles and make their own determination about the research quality of
candidates, when making labor market decisions, than they are to rely on
easily available indicators for research activity such as counts of
articles and of citations.
The results thus far do not consider vintage effects, with
quality-adjusted journal output aggregated into a single measure,
regardless of when articles published. The argument by Sgroi and Oswald
(2013) is that more weight over time ought to be put on the accrued
citations and less weight put on the journal where the article
published. Based on this reasoning, one could adopt a conservative rule
for academic labor market decisions, of letting article-specific quality
be revealed by citations before committing to costly salary decisions.
Indeed, the tenure system where new hires have 6 years to prove the
quality of their research before being offered a permanent appointment
might be broadly thought of in these terms. We are not advocating this
as a good description of how salary decisions are actually made, since
it would be undermined by a faculty member who scored a solid hit, such
as publishing in a top-5 journal, and threatened to leave for another
department that promotes based on expected research impact before
citations accumulate. Instead, we think of this as a scenario that
should give citations their best possible chance to show an influence on
academic salary.
Therefore, we recalculated the measure of lifetime production in
journals by ignoring articles published in either the prior 3 or prior 6
years. However, for the articles published by those cut-offs (that is,
by the end of 2004 or the end of 2007), we count all citations that had
accrued by the end of 2010. This calculation attempts to mimic the
conservative rule of waiting for the quality of an article to be
revealed by citations before making labor market decisions. The 6-year
period matches the typical length of time that new hires have on a
"tenure clock" while midterm reviews at 3 years are when
junior hires may consider moving to a lower ranked department and
resetting their tenure clock. Six years also corresponds to the typical
window used for research assessment exercises like the REF in the United
Kingdom. According to Sgroi and Oswald (2013), the earliest articles in
that window are ones where the greatest weight should be placed on their
accrued citations, and the least weight on where they were published.
The results of the salary equations with these new information sets
are in Panels B and C of Table 5. The results from Panel A of Table 3
that use all information on citations and articles to the end of 2010
are repeated for ease of comparison. Measures of (truncated) career
output in journals remain highly significant in all nine salary
equations. In contrast, the accumulated stock of citations is (weakly)
statistically significant in just three equations. In terms of
magnitudes, the average impact of quality-weighted journal output falls
slightly, from 0.091 to 0.085 to 0.079 if articles are considered to the
end of 2010, 2007, or 2004 while the citation impacts (counting to the
end of 2010) rise slightly, from 0.009 to 0.012 and 0.020. Nevertheless,
even with the most favorable assumption for citations, that articles
published in the last 6 years are ignored but citations to earlier
articles continue to be counted, it is still the case that citations
have impacts on salary that are just one-quarter of the impacts of
quality-adjusted journal output.
We also form weighted averages of citations and of quality-adjusted
journal output, in the spirit of Sgroi and Oswald (2013) who suggest
research evaluators should use such an approach. The aim is to find the
optimal weights on citations and on journals, in terms of maximizing the
log-likelihood of the salary equations. Rather than do this for all nine
weighting schemes, we use two that are toward opposite ends of the
spectrum for down-weighting lower ranked journals, CLm and KMS. It is
also the case that KMS shows some of the biggest effects for citations
and CLm some of the smallest. The maximized log-likelihoods are
illustrated in Figures 1A (CLm) and IB (KMS). This iterative search
procedure is repeated using the measures of lifetime journal output that
omit the articles published in the last 3 and 6 years (while citations
to earlier articles continue to accumulate), corresponding to the
analysis in Table 5.
With CLm weights, the optimal combination of citations and
quality-adjusted journals puts 2% weight on citations and 98% on
journals. Ignoring the last 3 years of articles, the weights are 4% and
96%, and with a very conservative rule of waiting 6 years before an
article is considered for influencing salary, to give time for citations
to accumulate, the weight on citations is just 11% while there is a 89%
weight on where the articles are published. (21) If the KMS weights are
used, results are a little more favorable for citations, which get
optimal weights of 17%, 16%, and 23% as ever more journal output is
ignored. (22)
The results thus far consider total citations but not their
distribution. Yet it may be the most heavily cited articles that show
research impact, which is the issue that the A-index and its generalized
variants are designed to deal with. We therefore carry out a further
three analyses that (a) consider total citations and the citations to
the most-cited article, (b) use the h-index for citations, and (c) use
the [h.sub.(5,2)] index that Ellison (2013) finds works best for senior
academics. Since the number of articles and the total quality-, size-,
and coauthor-adjusted pages in those articles are both statistically
significant, we continue to use these, so the baseline model, before the
distribution of citations is considered, is the one previously reported
in Panel A of Table 3.
Allowing for the distribution of citations does not change the
finding that salary depends on journal articles but is hardly affected
by citations. In Panel A of Table 6, we see that salary is higher if
there are more citations to the most-cited article, conditional on
journal output, while total citations have a negative but largely
insignificant effect. The Vuong tests show that a model using total
citations and citations to the most-cited article is significantly
rejected against models using the journals variables. In Panel B, the
h-index is not statistically significant, although its use does somewhat
weaken the Vuong test evidence in favor of the journals models.
Similarly, the generalized [h.sub.(5,2)] index in Panel C has no
significant effect on salary and using this generalized index tends to
strengthen the effect of the journals variables (and strengthens the
Vuong tests in favor of models using journals variables over those using
citations).
V. RECONCILIATION WITH PREVIOUS STUDIES
The results in Section IV suggest that, for UC economists,
citations hardly affect salary, especially in top-ranked departments.
This holds for various specifications of the citations variables, such
as using logs, prorating for coauthored articles, and using variants of
the h-index, and also holds in other sensitivity analyses. Impacts of
citations stay small, relative to those of quality-adjusted journals, if
recent articles are ignored while citations to older articles are
allowed to accrue. It is only in the lower ranked departments, and if
journal quality is less comprehensively measured, that effects of
citations on salary become larger, and comparable to effects of
journals. While these results have implications for several parts of the
literature, they differ in particular respects from five recent studies
(Ellison 2013; Hamermesh and Pfann 2012; Liebowitz 2014; Sgroi and
Oswald 2013; and HRH 2015). The aim of this section is to discuss
possible reasons for these differences and, where possible, to reconcile
our findings with the literature.
The easiest reconciliation is with Sgroi and Oswald (2013) who make
a normative point that research evaluators should put more weight on
citations over time and less weight on the journals where research was
published. Our results show that, irrespective of the logic of that
argument, citations do not seem to be used in this way for setting
salary of UC economists. It is also true that direct survey findings,
from Hamermesh and Pfann (2012) and Liebowitz (2014), support the
patterns we find, with far fewer departments relying on citations than
on information about journal articles, when making labor market
decisions.
The next easiest reconciliation is with Ellison (2013) who finds
academic labor market evidence in favor of generalized h-index measures
that concentrate attention on a few, highly cited, publications. In
contrast, the generalized measures provide no advantage over the
original h-index for explaining salaries of UC economists. This same
pattern occurs in a larger sample (HRH 2015). Both the current study and
HRH differ from Ellison (2013) in the labor market outcome studied, and
in their citations database, using WoS rather than Google Scholar. It is
not clear which difference matters most, and it is hard to
retrospectively create a database of Google Scholar citations with the
same timing as our WoS database (that ended in 2010) to explore this
further. Thus, future work could usefully create parallel databases from
Google Scholar and WoS in order to test if conclusions about labor
market payoffs to research quality depend on the citations database
used, helping to extend the limited comparisons in Hamermesh (2017).
The issue of how research-related determinants of faculty salary
vary with the rank of the department is the third area for reconciling
our findings with the literature. In the top-ranked UC departments,
citations do not seem to affect salaries while journal quality matters a
lot. In lower ranked UC departments citations become more important. We
show below that a similar pattern holds in the larger sample used by HRH
(2015). These results support Liebowitz (2014), who notes faculty in
lower ranked departments may be less likely to form their own
determination of the quality of a research record by reading the
articles, and instead may rely on easily available proxies, such as
counts of articles and of citations, when making labor market decisions.
They are less supportive of an argument of Hamermesh and Pfann (2012)
that higher ranked schools may put more weight on citations, since
citations contribute to reputation. In general, differences in salary
determination by school rank is an underresearched topic and one
advantage of studying a single university system like the UC is that
institutional factors, such as the UC system of merit pay rises, are
held constant while still having departments at widely different points
in the rankings.
The strand of the literature requiring the most effort to reconcile
with our results concerns the importance of citations as salary
determinants. Explicit comparisons of their impacts with those of
publications are rare, except in Hamermesh and Pfann (2012), but
implicit comparisons occur in papers that emphasize the role of
citations. For example, in the HRH (2015) results, adding article counts
(in journal tiers) to salary regressions did not affect the magnitude of
estimated citation effects, making it seem that publications are weak
and citations strong in explaining salary. As noted at multiple points
above, one reason the literature may support such claims is because of
imperfect controls for journal quality; since citations are correlated
with journal quality, the citations variables will pick up the slack.
For example, if quality-weighted journal output is dropped from the
models in Table 3A, and just a count of articles is used (following
Hamermesh and Pfann 2012), the citations coefficient increases almost
fourfold.
In order to further show that article counts in tiers are weak
controls for journal quality, we added the HRH journal tiers variables
and one of their specifications of citations (a quadratic in the
logarithm of citations plus one) to salary models, along with our
quality-weighted journals variables. (23) The results in Panel A of
Table 7 show that tier count variables are never statistically
significant while quality-weighted journals are statistically
significant in all but two equations. In other words, the approach used
to control for journal quality in much of the literature--counting
articles within journal tiers--ignores relevant information that instead
is captured by the size-, coauthor-, and quality-adjusted journal pages.
(24) Citations are correlated with quality-adjusted journal output so
omitting this relevant variable sees some of its effect picked up by
citations.
Since the journal tiers variables are statistically insignificant,
they are dropped in models reported in Panel B of Table 7. These models
have the HRH specification of citations variables along with our
specification of journals variables. The quality-adjusted journal output
variables are statistically significant at the 1% level in eight
equations and at the 5% level in the other, but the citations variables
are significant in just a single equation at the 10% level, using LP
weights. Thus, the result that salary of UC economists depends on
quality-adjusted journal output while citations hardly matter still
holds when using the HRH specification of citations variables. Also, the
HRH approach to measuring journal quality lacks explanatory power
compared to when formal journal assessment schemes are used to calculate
quality-weighted journal output.
To further advance the argument that how journal quality is
measured alters the apparent effect of citations, we obtained the data
that HRH (2015) use so we could supplement their salary equations with
our quality-weighted measures of journal output. (25) Specifically, we
use a model with the most comprehensive controls, reported in their
Table 6B, column (5), and we calculate a statistical indicator and an
economic indicator for the impact of adding their citations variables to
models where journal output is measured either using their tier counts
or our quality-weighted variables. The statistical indicator is the
incremental [R.sup.2] from adding the HRH citations variables (a
quadratic in the log of citations plus one). The results in Table 8 show
that apparent effects of citations are overstated by an average of 20%
if HRH journal tiers are used rather than using our quality-weighted
approach. The exaggeration of citation impacts from using journal tiers
is most, at 40%, when compared to using LP journal weights that
aggressively down-weight lower ranked journals. In contrast, MSF
weights, which are closer to an "all-journals-are-equal"
scheme, hardly change the estimated citation effects over what is seen
with the HRH journal tiers.
The economic indicator reported in Table 8 simulates the predicted
salary increase from a standard deviation rise in citations, using the
Duan (1983) method to predict level variables from log-dependent
variables. If journal output is controlled using HRH journal tiers,
predicted salary increases by $29,000 from a standard deviation increase
in citations. In contrast, the increase in predicted salary is just
$24,000 if journal output is controlled for using our quality-weighted
approach (with LP weights). Thus, the HRH tiers approach to measuring
journal output leads to a 20% overstatement in the estimated salary
impact of a citations shock.
In the remaining panels of Table 8, we repeat these exercises,
separately for top-ranked schools and other schools in the HRH sample.
The top-ranked schools are a better comparison to the UC sample, and
split-sample results also are motivated by the findings in Table 4 that
salary models differ by school rank. For the top schools in the HRH
sample, the way that one controls for journals has a big effect on the
apparent impact of citations; the incremental [R.sup.2] is about 60%
higher and the salary effect about 30% higher when using the HRH journal
tiers rather than using our quality-weighted approach (for the most
convex weights, such as LP and CLh). In contrast, for lower ranked
schools in the HRH sample, it does not matter which approach is used to
control for journals, with little variation across the nine sets of
journal weights or when using the HRH approach of counting articles
within journal tiers.
In Table 9, we expand upon this difference between top schools and
other schools, using the HRH model from their Table 6B, column (5) but
with our journal variables. (26) For top schools in the HRH sample, the
average effect of a standard deviation in quality-weighted journal
output is to raise salary by just over six log points. This is slightly
larger than the average marginal effect of citations (with the quadratic
evaluated at the mean). In contrast, for lower ranked schools,
quality-weighted journal output has no effect. The citations effects are
about the same for the two groups of schools, with average marginal
effects of 0.061 for top schools and 0.068 for lower ranked schools (in
terms of precision, squared citations are always highly significant for
lower ranked schools while hardly significant for the top schools). The
other difference between the salary models for the two groups of schools
is that the impact of article counts, with no splitting into journal
tiers, is roughly doubled for lower ranked schools.
The evidence in Table 9 suggests that in lower ranked schools in
the HRH sample, salary setting is more of a counting exercise, with
total counts of articles (with no quality tiers) and total counts of
citations affecting salary but no premium for journal quality. In
contrast, top schools in the HRH sample pay more according to journal
quality than to article counts. A lower premium for journal quality as
one move down the ranks of schools was also apparent in the UC data,
where salary at the top UC schools varied with quality-adjusted journal
output but hardly at all with citations, while for lower ranked UC
schools a mix of both citations and journals matter. These results help
account for why the UC sample has weaker effect of citations than the
HRH sample, even with the same controls for journals; the UC sample has
more top schools and these schools reward journal quality more than
citations. The lower ranked schools in the HRH sample dampen the
sensitivity of estimated citation impacts to different ways of
controlling for journal quality since those schools do not seem to pay a
premium for journal quality.
VI. CONCLUSIONS
The salary of UC economists depends far more on journal quality
than on citations. This pattern holds in many different sensitivity
analyses and even if recent articles are ignored while citations to
older articles are allowed to continue accumulating. It is only for the
lower ranked UC departments, or if journal quality is less
comprehensively controlled for, that effects of citations increase. For
example, if quality-weighted journal output is not accounted for,
estimated impacts of citations on salary increase almost fourfold.
The typical way that studies of economist salary control for
journal output is to count articles within tiers of journals. This
approach is imperfect because higher ranked journals are often omitted
from tiers and within-tier quality variation is ignored. Citations
correlate with journal quality, so using imperfect controls for journal
output increases estimated effects of citations. In both the UC sample
and the HRH sample, there is information that is relevant to salary that
is captured by size-, coauthor-, and quality-adjusted journal pages; if
this information is ignored, it leads to estimated impacts of citations
being overstated. This overstatement is especially apparent at top
schools where the returns to journal quality appear to be highest.
However, if the focus is on lower ranked schools, the different ways of
controlling for journal output may matter less since these schools do
not appear to reward publication in the highest ranked journals to the
same degree as do top schools.
ABBREVIATIONS
AER: American Economic Review
HRH: Hilmer, Ransom, and Hilmer (2015)
JEL: Journal of Economic Literature
NRC: National Research Council
QJE: Quarterly Journal of Economics
REF: Research Excellence Framework
UC: University of California
WoS: Web of Science
doi:10.1111/ecin.12453
APPENDIX
TABLE A1 Examples of the Journal Weights and Ranks, for
the 36 Journals Used by Hilmer, Ransom, and Hilmer (2015)
Journal MSF CLm CLh
Quarterly Journal of Economics 0.95 1.00 1.00
Journal of Political Economy 1.00 0.96 0.93
Econometrica 1.00 0.96 0.92
American Economic Review 1.00 0.98 0.96
Review of Economics & Statistics 0.92 0.74 0.55
Excellent Journal Group
Review of Economic Studies 0.86 0.81 0.66
Journal of Finance 0.89 0.72 0.52
Journal of Financial Economics 0.72 0.81 0.65
Journal of Monetary Economics 0.82 0.76 0.58
Rand Journal of Economics 0.83 0.64 0.41
Journal of Econometrics 0.81 0.69 0.47
Economic Journal 0.88 0.65 0.42
Journal of Economic Theory 0.87 0.73 0.53
Journal of Labor Economics 0.81 0.55 0.30
Journal of International Economics 0.76 0.62 0.38
International Economic Review 0.84 0.55 0.30
Journal of Public Economics 0.75 0.62 0.39
Journal of Money Credit & Banking 0.81 0.42 0.18
Journal of Law & Economics 0.81 0.41 0.17
Journal of Business & Economic Statistics 0.68 0.48 0.23
Journal of Human Resources 0.73 0.42 0.18
Journal of Business 0.76 0.29 0.09
Journal of Law, Economics & Organization 0.67 0.32 0.10
Journal of Development Economics 0.70 0.43 0.18
Journal of Economic Dynamics & Control 0.75 0.36 0.13
Journal of Urban Economics 0.72 0.40 0.16
Journal of International Money & Finance 0.78 0.23 0.05
Economica 0.83 0.27 0.07
Economic Inquiry 0.74 0.24 0.06
Industrial & Labor Relations Review 0.70 0.19 0.03
National Tax Journal 0.68 0.23 0.05
Journal of Legal Studies 0.64 0.16 0.03
Journal of Economic History 0.76 0.31 0.10
Southern Economic Journal 0.73 0.19 0.04
Public Choice 0.64 0.27 0.07
Journal of Regional Science 0.72 0.14 0.02
Journal RePEc Coupe K&Y_all
Quarterly Journal of Economics 1.00 0.59 0.86
Journal of Political Economy 0.52 0.43 0.64
Econometrica 0.83 0.41 0.44
American Economic Review 0.46 0.32 0.29
Review of Economics & Statistics 0.29 0.16 0.18
Excellent Journal Group
Review of Economic Studies 0.55 0.28 0.38
Journal of Finance 0.26 0.40 0.81
Journal of Financial Economics 0.49 0.37 0.84
Journal of Monetary Economics 0.50 0.20 0.24
Rand Journal of Economics 0.38 0.19 0.22
Journal of Econometrics 0.34 0.20 0.17
Economic Journal 0.33 0.22 0.12
Journal of Economic Theory 0.25 0.14 0.13
Journal of Labor Economics 0.48 0.21 0.13
Journal of International Economics 0.32 0.18 0.17
International Economic Review 0.22 0.13 0.18
Journal of Public Economics 0.30 0.14 0.11
Journal of Money Credit & Banking 0.20 0.15 0.16
Journal of Law & Economics 0.21 0.21 0.12
Journal of Business & Economic Statistics 0.31 0.18 0.15
Journal of Human Resources 0.26 0.21 0.12
Journal of Business 0.14 0.18 0.37
Journal of Law, Economics & Organization 0.21 0.21
Journal of Development Economics 0.21 0.11 0.07
Journal of Economic Dynamics & Control 0.16 0.09 0.07
Journal of Urban Economics 0.15 0.13 0.05
Journal of International Money & Finance 0.20 0.10 0.07
Economica 0.13 0.10 0.03
Economic Inquiry 0.11 0.11 0.04
Industrial & Labor Relations Review 0.08 0.25 0.07
National Tax Journal 0.09 0.11 0.05
Journal of Legal Studies 0.08 0.53
Journal of Economic History 0.01 0.12 0.05
Southern Economic Journal 0.07 0.07 0.05
Public Choice 0.06 0.06 0.02
Journal of Regional Science 0.06 0.09 0.01
Journal K&Y_econ KMS LP
Quarterly Journal of Economics 0.78 0.60 0.42
Journal of Political Economy 0.59 0.41 0.63
Econometrica 0.41 0.45 0.78
American Economic Review 0.27 1.00 0.40
Review of Economics & Statistics 0.18 0.24 0.07
Excellent Journal Group
Review of Economic Studies 0.37 0.33 0.41
Journal of Finance 0.60 0.34
Journal of Financial Economics 0.64 0.16 1.00
Journal of Monetary Economics 0.23 0.28 0.42
Rand Journal of Economics 0.20 0.13 0.40
Journal of Econometrics 0.16 0.16 0.19
Economic Journal 0.12 0.21 0.08
Journal of Economic Theory 0.13 0.23 0.35
Journal of Labor Economics 0.13 0.09 0.15
Journal of International Economics 0.16 0.19 0.08
International Economic Review 0.17 0.12 0.12
Journal of Public Economics 0.11 0.22 0.09
Journal of Money Credit & Banking 0.15 0.12 0.09
Journal of Law & Economics 0.09 0.03 0.12
Journal of Business & Economic Statistics 0.15 0.07 0.08
Journal of Human Resources 0.11 0.08 0.05
Journal of Business 0.26 0.21
Journal of Law, Economics & Organization 0.03
Journal of Development Economics 0.07 0.10 0.01
Journal of Economic Dynamics & Control 0.06 0.07 0.05
Journal of Urban Economics 0.05 0.05 0.02
Journal of International Money & Finance 0.06
Economica 0.03 0.02 0.03
Economic Inquiry 0.04 0.04 0.04
Industrial & Labor Relations Review 0.07 0.04
National Tax Journal 0.05 0.02 0.00
Journal of Legal Studies 0.02
Journal of Economic History 0.05 0.04 0.03
Southern Economic Journal 0.05 0.02 0.01
Public Choice 0.02 0.04 0.02
Journal of Regional Science 0.01 0.01 0.00
Journal Mean Highest
Weight Rank
Quarterly Journal of Economics 0.80 1
Journal of Political Economy 0.68 1
Econometrica 0.69 1
American Economic Review 0.63 1
Review of Economics & Statistics 0.37 6
Excellent Journal Group
Review of Economic Studies 0.51 5
Journal of Finance 0.57 4
Journal of Financial Economics 0.63 1
Journal of Monetary Economics 0.45 4
Rand Journal of Economics 0.38 7
Journal of Econometrics 0.35 11
Economic Journal 0.34 10
Journal of Economic Theory 0.37 8
Journal of Labor Economics 0.32 13
Journal of International Economics 0.32 12
International Economic Review 0.29 14
Journal of Public Economics 0.30 9
Journal of Money Credit & Banking 0.25 19
Journal of Law & Economics 0.24 19
Journal of Business & Economic Statistics 0.26 22
Journal of Human Resources 0.24 25
Journal of Business 0.29 11
Journal of Law, Economics & Organization 0.26 31
Journal of Development Economics 0.21 23
Journal of Economic Dynamics & Control 0.19 28
Journal of Urban Economics 0.19 28
Journal of International Money & Finance 0.22 24
Economica 0.17 15
Economic Inquiry 0.16 36
Industrial & Labor Relations Review 0.18 27
National Tax Journal 0.14 52
Journal of Legal Studies 0.24 6
Journal of Economic History 0.16 30
Southern Economic Journal 0.14 37
Public Choice 0.13 45
Journal of Regional Science 0.12 41
Journal Lowest Mean
Rank Rank
Quarterly Journal of Economics 5 2
Journal of Political Economy 10 5
Econometrica 11 5
American Economic Review 16 8
Review of Economics & Statistics 59 20
Excellent Journal Group
Review of Economic Studies 22 9
Journal of Finance 30 11
Journal of Financial Economics 43 12
Journal of Monetary Economics 41 14
Rand Journal of Economics 42 18
Journal of Econometrics 37 19
Economic Journal 30 20
Journal of Economic Theory 70 23
Journal of Labor Economics 36 23
Journal of International Economics 52 24
International Economic Review 83 28
Journal of Public Economics 72 28
Journal of Money Credit & Banking 64 30
Journal of Law & Economics 46 31
Journal of Business & Economic Statistics 53 31
Journal of Human Resources 39 31
Journal of Business 65 35
Journal of Law, Economics & Organization 55 41
Journal of Development Economics 93 44
Journal of Economic Dynamics & Control 109 44
Journal of Urban Economics 79 46
Journal of International Money & Finance 98 56
Economica 101 60
Economic Inquiry 96 61
Industrial & Labor Relations Review 110 61
National Tax Journal 91 65
Journal of Legal Studies 109 73
Journal of Economic History 290 75
Southern Economic Journal 143 80
Public Choice 148 83
Journal of Regional Science 155 111
Notes: Weights are indexed so that the highest weighted
journal = 1.00. Missing values are journals excluded from
a particular scheme. Highest, lowest, and mean rank allow
for ties. Sources for each weighting scheme in text.
REFERENCES
Anderson, D., W. Smart, and J. Tressler. "Evaluating
Research--Peer Review Team Assessment and Journal Based Bibliographic
Measures: New Zealand PBRF Research Output Scores in 2006." New
Zealand Economic Papers, 47(2), 2013, 140-57.
Bratsberg, B., J. Ragan, and J. Warren. "Negative Returns to
Seniority: New Evidence in Academic Markets." Industrial and Labor
Relations Review, 56(2), 2003, 306-23.
--. "Does Raiding Explain the Negative Returns to Faculty
Seniority?" Economic Inquiry, 48(3), 2010, 704-21.
Bruns, S., and D. Stem. "Research Assessment Using Early
Citation Information." Scientometrics, 108(2), 2016, 917-35.
Combes, P-P., and L. Linnemer. "Inferring Missing Citations: A
Quantitative Multi-Criteria Ranking of all Journals in Economics."
Groupement de Recherche en Economie Quantitative d'Aix Marseille
(GREQAM), Document de Travail, no. 2010-28, 2010.
Coupe, T. "Revealed Performances: Worldwide Rankings of
Economists and Economics Departments, 1990-2000." Journal of the
European Economic Association, 1(6), 2003, 1309-45.
Duan, N. "Smearing Estimate: A Nonparametric Retransformation
Method." Journal of the American Statistical Association, 78(383),
1983, 605-10.
Ellison, G. "Evolving Standards for Academic Publishing: A q-r
Theory." Journal of Political Economy, 110(5), 2002, 994-1034.
--. "How Does the Market Use Citation Data? The Hirsch Index
in Economics." American Economic Journal: Applied Economics, 5(3),
2013, 63-90.
Gibson, J. "Returns to Articles versus Pages in Academic
Publishing: Do Salary-Setters Show 'Article Illusion'?"
Economics Letters, 125(3), 2014, 343-46.
Gibson, J., D. Anderson, and J. Tressler. "Which Journal
Rankings Best Explain Academic Salaries? Evidence from the University of
California." Economic Inquiry, 52(4), 2014, 1322-40.
Hamermesh, D. "Citations in Economics: Measurement, Uses and
Impacts." Journal of Economic Literature, 2017.
Hamermesh, D., and G. Pfann. "Reputation and Earnings: The
Roles of Quality and Quantity in Academe." Economic Inquiry, 50(1),
2012, 1-16.
Hamermesh, D., G. Johnson, and B. Weisbrod. "Scholarship,
Citations and Salaries: Economic Rewards in Economics." Southern
Economic Journal, 49(3), 1982, 472-81.
Hicks, D. "Performance-Based University Research Funding
Systems." Research Policy, 41(2), 2012, 251-61.
Hilmer, C., and M. Hilmer. "How Do Journal Quality,
Co-Authorship, and Author Order Affect Agricultural Economists'
Salaries?" American Journal of Agricultural Economics, 87(2), 2005,
509-23.
--. "Negative Returns to Seniority and Job Mobility across the
Program Quality Distribution: Are Top Public PhD-Granting Programs
Different?" American Economic Review: Papers and Proceedings,
101(3), 2011, 466-70.
Hilmer, C., M. Hilmer, and J. Lusk. "A Comparison of Salary
Structures between Economics and Agricultural Economics
Departments." Applied Economic Perspectives and Policy, 34(3),
2012, 489-514.
Hilmer, M., M. Ransom, and C. Hilmer. "Fame and the Fortune of
Academic Economists: How the Market Rewards Influential Research in
Economics." Southern Economic Journal, 82(2), 2015,430-52.
Hirsch, J. "An Index to Quantify an Individual's
Scientific Research Output." Proceedings of the National Academy of
Science, 102(46), 2005, 16569-72.
Kalaitzidakis, P., T. Mamuneas, and T. Stengos. "An Updated
Ranking of Academic Journals in Economics." Working Paper 9/2010,
Economics Department, University of Guelph, Guelph, Canada, 2010.
Kodrzycki, Y., and P. Yu. "New Approaches to Ranking Economics
Journals." B.E. Journal of Economic Analysis and Policy:
Contributions to Economic Analysis and Policy, 5(1), 2006, Article 24.
Laband, D., and M. Piette. "The Relative Impact of Economics
Journals." Journal of Economic Literature, 32(2), 1994, 640-66.
Liebowitz, S. "Our Uneconomic Methods of Measuring Economic
Research." Voxeu December 6, 2013. Accessed June 2015.
http://www.voxeu.org/article/ouruneconomic-methodsmeasuring-economic-research.
--. "Willful Blindness: The Inefficient Reward Structure in
Academic Research." Economic Inquiry, 52(4), 2014, 1267-83.
Liebowitz, S., and J. Palmer. "Assessing the Relative Impacts
of Economics Journals." Journal of Economic Literature, 22(1),
1984, 77-88.
Macri, J., and D. Sinha. "Rankings Methodology for
International Comparisons of Institutions and Individuals: An
Application to Economics in Australia and New Zealand." Journal of
Economic Surveys, 20(1), 2006, 111-56.
Mason, P., J. Steagall, and M. Fabritius. "Economics Journal
Rankings by Type of School: Perceptions versus Citations."
Quarterly Journal of Business and Economics, 36(1), 1997, 69-79.
Moore, W., R. Newman, and G. Turnbull. "Do Academic Salaries
Decline with Seniority?" Journal of Labor Economics, 16(2), 1998,
352-66.
--. "Reputational Capital and Academic Pay." Economic
Inquiry, 39(4), 2001, 663-71.
Ransom, M. "Seniority and Monopsony in the Academic Labor
Market." American Economic Review, 83(1), 1993,221-33.
Sauer, R. "Estimates of the Returns to Quality and
Co-authorship in Economic Academia." Journal of Political Economy,
96(4), 1988, 855-66.
Scott, L., and P. Mitias. "Trends in Rankings of Economics
Departments in the U.S.: An Update." Economic Inquiry, 34(3), 1996,
378-400.
Sgroi, D., and A. Oswald. "How Should Peer-review Panels
Behave?" Economic Journal, 123(570), 2013, F255-78.
Spiegel, M. "Reviewing Less--Progressing More." Review of
Financial Studies, 25(5), 2012, 1331-38.
Vuong, Q. "Likelihood Ratio Tests for Model Selection and
Non-nested Hypotheses." Econometrica, 57(2), 1989, 307-33.
Wilhite, A. W., and E. A. Fong. "Coercive Citation in Academic
Publishing." Science, 355, 2012, 542-43.
JOHN GIBSON, DAVID L. ANDERSON and JOHN TRESSLER *
* We are grateful to audiences at Monash and the WEAI conference,
and especially to two anonymous referees and the editor for helpful
comments. We particularly acknowledge the assistance of Michael Ransom
and his coauthors in providing the data from their study. All remaining
errors are those of the authors.
Gibson: Professor, Department of Economics, Waikato Management
School, University of Waikato, Hamilton 3240, New Zealand. Phone 64 7
838 4289, Fax 64 7 838 4331, E-mail jkgibson@ waikato.ac.nz
Anderson: Emeritus Professor, Smith School of Business,
Queen's University, Kingston K7L 3N6, Canada. Phone 1-790-470-0408,
Fax 1-613-533-2301, E-mail dla@queensu.ca
Tressler: Research Associate, Department of Economics, Waikato
Management School, University of Waikato, Hamilton 3240, New Zealand.
Phone 64 7 856 2889, Fax 64 7 838 4331, E-mail tressler@waikato.ac.nz
(1.) In terms of timeliness, long-run citations in economics are
predictable from early citations (Bruns and Stem 2016).
(2.) Of course, citations may also be prone to manipulation.
Wilhite and Fong (2012) highlight coercing journals, while Ellison
(2002) and Spiegel (2012) highlight the growth in the length of
bibliographies, which may reflect a response by authors to an expected
desire of editors and potential referees to be cited. We leave it for
future work to assess whether citations or publications are more prone
to manipulation.
(3.) For example, they may focus on things such as the returns to
seniority (Ransom 1993; Moore, Newman, and Turnbull 1998; Bratsberg,
Ragan, and Warren 2003, 2010; Hilmer and Hilmer 2011) or on effects of
coauthorship (Sauer 1988; Moore, Newman, and Turnbull 2001; Hilmer and
Hilmer 2005).
(4.) This is based on the same salary and publications data as
Gibson, Anderson, and Tressler (2014) but adds the citations data and
omits Assistant Professors who typically have not accumulated many
citations.
(5.) According to the National Research Council (NRC) ranks, the
top half of schools in the HRH sample is a better comparator to the UC
schools.
(6.) The journal of publication is a less easily used proxy for
quality, since there is no agreement on ranks beyond the top-5 journals,
nor agreement on weights for converting output from one journal to
another. Thus, there is still a need for user judgment and this need is
increased by dynamics in the journal marketplace. Debates about where to
rank new journals like the American Economic Journals, or when societies
break from publishers (e.g., European Economic Review versus Journal of
the European Economic Association or Journal of Environment Economics
and Management versus Journal of the Association of Environmental and
Resource Economists) show this uncertainty. Indeed, the diversity of
views about journals is one reason why we use nine different assessment
schemes.
(7.) Widely used journal rankings and weights are provided by:
Mason, Steagall, and Fabritius (1997), Combes and Linnemer (2010), Coupe
(2003), Kodrzcki and Yu (2006), Kalaitzidakis, Mamuneas, and Stengos
(2010), and Laband and Piette (1994).
(8.) Bratsberg, Ragan, and Warren (2003) summarize nine, earlier,
seniority studies.
(9.) Moore, Newman, and Turnbull (2001), Bratsberg, Ragan, and
Warren (2003, 2010), Hilmer and Hilmer (2005), Hilmer, Hilmer, and Lusk
(2012), and HRH (2015) are further examples.
(10.) These studies had useful innovations, by accounting for
coauthorship and the different size of articles. These are two of the
three adjustments that we make, but neglect the most important, which is
the quality weights for journals.
(11.) Specifically, a search over values between 0 and 1 for an
exponent to the weights yields an optimal [alpha] = .3.
(12.) Hamermesh (2017) shows that for a sample of younger faculty
from top-30 economics departments with Google Scholar profiles, their
citations in Web of Science increase at a rate of just 17.3 per 100
citations in Google Scholar.
(13.) We use "items" rather than "articles" to
describe the data used by HRH (2015) because they include book reviews,
editorials, announcements, and other nonarticle material that WoS
attributes to authors.
(14.) A previous version included a quadratic in seniority but a
referee urged that this be dropped since (low) seniority conditional on
experience is likely to proxy for quality of that particular academic,
and therefore is likely to be correlated with publications and
citations. Our main results are not changed by including or excluding
seniority.
(15.) For example, 13 of the 31 journals in the HRH
"excellent" tier have incomplete coverage in WoS. Mostly this
is for newer journals which had published for an average of 5 years (and
a range from 2 to 12) before being included.
(16.) These quality weights are as originally published. We have
not attempted to update these with more recent data.
(17.) There is mixed evidence on whether coauthored articles are
fully prorated (Hilmer, Hilmer, and Lusk 2012; Liebowitz 2014). For UC
economists, Gibson, Anderson, and Tressler (2014) show tests for
prorating depend on whether older articles are discounted.
(18.) Model comparison and non-nested tests for a larger sample of
UC economists that included Assistant Professors also showed that the
CLm journal weights were the ones most congruent with the salary data
(Gibson, Anderson, and Tressler 2014).
(19.) If the quality-adjusted journals variable is omitted, and
just counts of articles and of citations are used, the coefficient on
citations increases almost fourfold over its average in Table 3A, to a
statistically significant 0.036.
(20.) We are grateful to an anonymous referee for this argument,
which is that someone hired at a prestigious school without a strong
publication or citation record must have a component of their
productivity that is observable to colleagues in the hiring department
but not observable to us in the record of their journal articles and
citations.
(21.) Using this rule also lowers the log-likelihood a lot (Figure
1A), showing the unreality of these assumptions.
(22.) Figure 1 includes article counts, which remain significant
even with the last 6 years of articles excluded. If the counts are
omitted, the optimal weights on citations are 2%, 3%, and 9% (CLm) and
23%, 22%, and 26% (KMS).
(23.) We prefer this to using the h-index, since the h-index also
depends, partly, on the number of articles and so may not be a pure
measure of citations, as Hamermesh and Pfann (2012) also argue.
(24.) The statistical significance of the total count of
articles--with no differentiation into journal tiers--for the journal
assessment schemes that are most convex (LP, KMS, K&Y, and CLh)
suggests that quality and quantity of journal output is relevant to pay,
as also shown in Gibson (2014) but this pattern also is hidden by the
journal tiers approach.
(25.) We are grateful to Michael Ransom and coauthors for providing
these data, which consisted of an estimation file and two publications
databases. The databases included items not in the UC data, like book
reviews and editorials. We created our quality-weighted journals
measures for supplementing the HRH salary equations just from articles
meeting the standards applied to the UC data; there are about 15% fewer
of these than of the items used by HRH.
(26.) This is analogous to Panel B of Table 7 for the UC data,
except that here we include the quadratic in seniority so as to maintain
comparability with the HRH specification.
Caption: FIGURE 1 Optimally Weighted Combinations of Citations and
Quality-Adjusted Journal Output
TABLE 1
Variable Definitions, Means, and Standard Deviations
Variable Mean Std Dev
Salary 173.35 55.89
Number of articles 32.57 24.80
Citations to those articles 827.47 1464.55
Citations to most-cited article 201.08 49.22
h-index 11.33 6.81
[h.sub.(5,2)]-index 2.53 1.21
Not-ISI 0.12 0.12
Quality-, size-, and coauthor-adjusted journal output
(lifetime AER-sized pages) using journal weights from
MSF 174.47 136.14
CLm 129.41 98.33
CLh 85.35 71.88
RePEc 79.98 71.05
Coupe 55.89 49.10
K&Y_all 48.73 46.21
K&Y econ 45.15 42.78
KMS 47.05 41.35
LP 44.11 42.15
Control variables
Experience (years) 22.66 10.86
Male 0.86 0.35
Not standard pay scale 0.04 0.19
Variable Description
Salary Base salary in 2010 ($,000)
Number of articles Career total articles
Citations to those articles Total WoS citations to those
articles to end of 2010
Citations to most-cited article Total WoS citations to the
most-cited article
h-index Economist has h articles with h
or more citations
[h.sub.(5,2)]-index Generalized fi-index; h articles
with 5 [h.sup.2] citations
Not-ISI Share of journals not in WoS
(so zero cites recorded)
Quality-, size-, and coauthor-adjusted journal output
(lifetime AER-sized pages) using journal weights from
MSF Mason, Steagall and Fabritius
reputational ranking
CLm Combes-Linnemer medium-convexity
weights
CLh Combes-Linnemer high convexity
weights
RePEc RePEc Simple Impact Factor
Coupe Average of 2-year impact factors
for 1994-2000
K&Y_all Kodrzycki and Yu eigenfactor
ranks, cites from all journals
K&Y econ Kodrzycki and Yu ranks, cites just
from econ journals
KMS Kalaitzidakis, Mamuneas and
Stengos eigenfactor weights
LP Laband and Piette eigenfactor
weights
Control variables
Experience (years) Years since first appointment
Male Person is male (=1) or female (=0)
Not standard pay scale Not on a standard, 9-month,
academic year pay scale
Note: N = 167.
TABLE 2
Salary Regressions for Tenured UC Economists Using Lifetime
Quality-Adjusted Journal Output and WoS Citations
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
Quality-adjusted journals 0.132 0.148 0.127
(6.77) *** (7.06) *** (5.10) ***
Total citations 0.014 0.003 0.009
(0.89) (0.16) (0.53)
Experience (years) 0.015 0.012 0.017
(2.54) ** (2.06) ** (2.88) ***
Experience squared -0.027 -0.021 -0.028
(2.36) ** (1.88) * (2.50) **
Male 0.026 0.012 0.020
(0.56) (0.25) (0.42)
Constant 11.958 11.970 11.898
[R.sup.2] (142.02) *** (140.09) *** (137.07) ***
0.677 0.684 0.659
Vuong non-nested test (a) 3.12 *** 3.53 *** 2.90 ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
Quality-adjusted journals 0.117 0.119 0.113
(5.94) *** (5.83) *** (6.08) ***
Total citations 0.020 0.025 0.025
(1.32) (1.62) (1.76) *
Experience (years) 0.016 0.018 0.019
(2.80) *** (3.09) *** (3.29) ***
Experience squared -0.027 -0.032 -0.031
(2.40) ** (2.85) *** (2.81) ***
Male 0.022 0.035 0.025
(0.47) (0.72) (0.52)
Constant 11.910 11.892 11.872
[R.sup.2] (139.32) *** (141.34) *** (139.50) ***
0.657 0.660 0.655
Vuong non-nested test (a) 2.66 *** 2.46" 2.64 ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
Quality-adjusted journals 0.112 0.097 0.112
(5.91) *** (4.81) *** (4.20) ***
Total citations 0.026 0.030 0.013
(1.80) * (2.02) ** (0.60)
Experience (years) 0.019 0.020 0.021
(3.24) *** (3.33) *** (3.53) ***
Experience squared -0.031 -0.032 -0.036
(2.77) *** (2.85) *** (3.16) ***
Male 0.026 0.024 0.032
(0.53) (0.47) (0.65)
Constant 11.876 11.876 11.865
[R.sup.2] (139.45) *** (132.73) *** (135.59) ***
0.654 0.639 0.641
Vuong non-nested test (a) 2.62 ** 1.92 * 2.22 **
Notes: Dependent variable is log of base salary for the
2010 academic year, as reported at: http://www.sacbee.com/statepay/
and journal output and the number of citations are standardized so
coefficients show the impact of a one standard deviation change.
Fixed effects for each UC campus (with UC Berkeley the omitted
category), an indicator for academics not on standard contracts,
and an indicator for the proportion of published articles not in
WoS journals (so citations appear zero) are not reported.
N = 167 associate and full professors, robust r-statistics
in parentheses.
(a) The Vuong non-nested test is for comparing a model using
journal output versus a model using citations (with both models
having all of the other control variables); it is distributed
as a z-statistic, with significant positive values favoring the
journals model over the citations model.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
TABLE 3
Sensitivity Analyses for Salary Regressions Using Lifetime
Quality-Adjusted Journal Output and WoS Citations
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Including the count of articles as a covariate
Quality-adjusted journals 0.108 0.123 0.096
(4.44) *** (5.00) *** (4.38) ***
Total citations 0.013 0.003 0.001
(0.86) (0.18) (0.03)
Number of articles 0.033 0.037 0.077
(1.50) (1.80) * (4.47) ***
[R.sup.2] 0.679 0.688 0.682
B. Using log-transformed citations (following HRH 2015)
Quality-adjusted journals 0.095 0.109 0.083
(3.59) *** (4.14) *** (3.59) ***
ln(citations + 1) 0.079 0.054 0.056
(1.25) (0.81) (0.81)
Number of articles 0.029 0.034 0.069
[R.sup.2] (1.26) (1.57) (3.41) ***
0.683 0.690 0.685
C. Using prorated citations
Quality-adjusted journals 0.112 0.129 0.101
(4.64) *** (5.25) *** (4.58) ***
Total citations per author 0.005 -0.006 -0.008
(0.42) (0.50) (0.61)
Number of articles 0.034 0.036 0.077
[R.sup.2] (1.52) (1.77) * (4.60) ***
0.678 0.688 0.683
D. Including controls for the most frequent JEL letter
category used in published articles by each academic
Quality-adjusted journals 0.120 0.125 0.097
(4.14) *** (4.50) *** (3.91) ***
Total citations 0.008 -0.001 -0.002
(0.50) (0.04) (0.13)
Number of articles 0.030 0.037 0.077
(1.10) (1.58) (3.89) ***
[R.sup.2] 0.704 0.708 0.702
E. Including diversity index for lifetime articles
(based on 137 JEL 2-digit categories)
Quality-adjusted journals 0.100 0.117 0.091
(4.11) *** (4.66) *** (4.13) ***
Total citations 0.016 0.005 0.003
(101) (0.33) (0.20)
Number of articles 0.034 0.035 0.072
(1.52) (1.69) * (4.17) ***
Diversity index 0.002 0.002 0.002
(1.49) (1.76) * (1.81) *
[R.sup.2] 0.683 0.693 0.688
F. Omitting fixed effects for each campus
Quality-adjusted journals 0.182 0.212 0.184
(5.59) *** (6.15) *** (5.56) ***
Total citations 0.015 -0.009 -0.021
(0.77) (0.50) (1.11)
Number of articles -0.022 -0.023 0.039
(0.68) (0.78) (1.63)
[R.sup.2] 0.409 0.449 0.462
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Including the count of articles as a covariate
Quality-adjusted journals 0.080 0.081 0.083
(4.27) *** (3.67) *** (4.79) ***
Total citations 0.015 0.021 0.014
(0.93) (1.27) (0.90)
Number of articles 0.068 0.060 0.077
(3.36) *** (2.84) *** (4.09) ***
[R.sup.2] 0.673 0.670 0.678
B. Using log-transformed citations (following HRH 2015)
Quality-adjusted journals 0.068 0.068 0.072
(3.38) *** (2.64) *** (3.91) ***
ln(citations + 1) 0.087 0.094 0.077
(1.37) (1.44) (1.21)
Number of articles 0.060 0.054 0.069
[R.sup.2] (2.70) *** (2.38) ** (3.15) ***
0.678 0.675 0.682
C. Using prorated citations
Quality-adjusted journals 0.083 0.083 0.085
(4.44) *** (3.81) *** (4.95) ***
Total citations per author 0.008 0.014 0.007
(0.70) (1.18) (0.64)
Number of articles 0.069 0.062 0.079
[R.sup.2] (3.44) *** (2.95) *** (4.23) ***
0.672 0.669 0.677
D. Including controls for the most frequent JEL letter
category used in published articles by each academic
Quality-adjusted journals 0.085 0.082 0.087
(3.64) *** (3.33) *** (4.18) ***
Total citations 0.011 0.017 0.009
(0.64) (0.99) (0.53)
Number of articles 0.069 0.065 0.078
(2.78) *** (2.45) ** (3.48) ***
[R.sup.2] 0.694 0.692 0.699
E. Including diversity index for lifetime articles
(based on 137 JEL 2-digit categories)
Quality-adjusted journals 0.075 0.074 0.077
(3.96) *** (3.27) *** (4.41) ***
Total citations 0.017 0.023 0.016
(109) (1.41) (1.06)
Number of articles 0.065 0.059 0.074
(3.18) *** (2.76) *** (3.91) ***
Diversity index 0.002 0.002 0.002
(1.89) * (1.75) * (1.62)
[R.sup.2] 0.679 0.676 0.683
F. Omitting fixed effects for each campus
Quality-adjusted journals 0.164 0.164 0.157
(6.58) *** (7.10) *** (7.12) ***
Total citations 0.004 0.016 0.003
(0.25) (0.94) (0.20)
Number of articles 0.020 0.003 0.041
(0.79) (0.11) (1.84) *
[R.sup.2] 0.430 0.421 0.446
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Including the count of articles as a covariate
Quality-adjusted journals 0.082 0.070 0.098
(4.71) *** (4.01) *** (4.05) ***
Total citations 0.014 0.014 -0.010
(0.93) (0.91) (0.51)
Number of articles 0.077 0.089 0.098
(4.09) *** (4.72) *** (5.74) ***
[R.sup.2] 0.677 0.671 0.684
B. Using log-transformed citations (following HRH 2015)
Quality-adjusted journals 0.071 0.057 0.080
(3.85) *** (2.88) *** (3.45) ***
ln(citations + 1) 0.078 0.080 0.052
(1.23) (1.21) (0.74)
Number of articles 0.069 0.079 0.087
[R.sup.2] (3.15) *** (3.61) *** (3.99) ***
0.681 0.675 0.686
C. Using prorated citations
Quality-adjusted journals 0.084 0.072 0.105
(4.86) *** (4.17) *** (4.28) ***
Total citations per author 0.008 0.007 -0.019
(0.68) (0.59) (1.22)
Number of articles 0.079 0.091 0.100
[R.sup.2] (4.23) *** (4.90) *** (6.02) ***
0.677 0.671 0.685
D. Including controls for the most frequent JEL letter
category used in published articles by each academic
Quality-adjusted journals 0.086 0.072 0.097
(4.12) *** (3.43) *** (3.41) ***
Total citations 0.010 0.010 -0.009
(0.58) (0.63) (0.43)
Number of articles 0.078 0.09 0.096
(3.48) *** (4.09) *** (4.87) ***
[R.sup.2] 0.698 0.693 0.701
E. Including diversity index for lifetime articles
(based on 137 JEL 2-digit categories)
Quality-adjusted journals 0.076 0.063 0.097
(4.35) *** (3.61) *** (4.00) ***
Total citations 0.017 0.017 -0.008
(1.09) (1.10) (0.42)
Number of articles 0.074 0.085 0.092
(3.91) *** (4.45) *** (5.34) ***
Diversity index 0.002 0.002 0.003
(1.66) * (1.68) * (2.35) **
[R.sup.2] 0.682 0.676 0.692
F. Omitting fixed effects for each campus
Quality-adjusted journals 0.156 0.143 0.196
(6.88) *** (5.50) *** (7.01) ***
Total citations 0.004 0.004 -0.046
(0.23) (0.24) (2.26) **
Number of articles 0.041 0.059 0.079
(1.84) * (2.56) ** (3.95) ***
[R.sup.2] 0.445 0.424 0.492
Notes: Each regression also includes all of the other
variables from Table 2.N= 167, robust t-statistics
in parentheses.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
TABLE 4
Citations Appear to Be a More Important Influence
on Salary in Lower Ranked Departments
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Using the subsample from the top four
departments (Berkeley, UCSD, UCLA, UC Davis)
Quality-adjusted journals 0.148 0.156 0.130
(6.19) *** (5.98) *** (4.59) ***
Total citations 0.003 -0.005 0.004
(0.18) (0.28) (0.24)
[R.sup.2] 0.702 0.704 0.675
B. Using the sub-sample from economics
departments at the other (lower ranked) UC campuses
Quality-adjusted journals 0.089 0.101 0.093
(2.37) ** (2.63) ** (2.27) **
Total citations 0.083 0.077 0.083
(2.13) ** (1.91) * (2.34) **
[R.sup.2] 0.609 0.618 0.611
C. Interaction effects between Top 4 indicator
and quality-adjusted journals and citations
(i.e., test of A-B differences)
Quality-adjusted journals 0.037 0.027 0.020
(0.83) (0.54) (0.33)
Total citations -0.230 -0.225 -0.224
(2.53) ** (2.40) ** (2.75) ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Using the subsample from the top four
departments (Berkeley, UCSD, UCLA, UC Davis)
Quality-adjusted journals 0.130 0.138 0.120
(5.77) *** (6.19) *** (5.88) ***
Total citations 0.013 0.018 0.022
(0.89) (1.14) (1.40)
[R.sup.2] 0.684 0.694 0.678
B. Using the sub-sample from economics
departments at the other (lower ranked) UC campuses
Quality-adjusted journals 0.065 0.066 0.067
(1.95) * (1.51) (1.89) *
Total citations 0.095 0.091 0.093
(2.89) *** (2.24) ** (2.78) ***
[R.sup.2] 0.586 0.582 0.586
C. Interaction effects between Top 4 indicator
and quality-adjusted journals and citations
(i.e., test of A-B differences)
Quality-adjusted journals 0.066 0.061 0.054
(1.72) * (1.21) (1.36)
Total citations -0.109 -0.097 -0.096
(3.05) *** (2.23) ** (2.65) ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Using the subsample from the top four
departments (Berkeley, UCSD, UCLA, UC Davis)
Quality-adjusted journals 0.119 0.089 0.145
(5.72) *** (3.79) *** (4.41) ***
Total citations 0.022 0.031 -0.007
(1.43) (1.92) * (0.41)
[R.sup.2] 0.677 0.644 0.673
B. Using the sub-sample from economics
departments at the other (lower ranked) UC campuses
Quality-adjusted journals 0.069 0.075 0.075
(1.98) * (2.02) ** (1.90) *
Total citations 0.092 0.092 0.098
(2.72) *** (3.02) *** (3.70) ***
[R.sup.2] 0.588 0.595 0.601
C. Interaction effects between Top 4 indicator
and quality-adjusted journals and citations
(i.e., test of A-B differences)
Quality-adjusted journals 0.051 0.018 0.042
(1.27) (0.47) (0.92)
Total citations -0.094 -0.082 -0.118
(2.57) *** (2.32) ** (3.59) ***
Notes: Each regression in Panel A and B also includes all
of the other variables from Table 2, while in Panel C the
specification from Table 2 is augmented with an indicator
for the top four departments and the interaction terms between
that indicator and quality-adjusted journals and total citations.
N = 104 in the top four and N = 63 in the other five departments.
Robust t-statistics in parentheses.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
TABLE 5
Salary Regressions Comparing Impact of Journal Articles
and WoS Citations for Articles of Different Vintages
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Results from Table 3A, including
articles published until end of 2010
Quality-adjusted journals 0.108 0.123 0.096
(4.44) *** (5.00) *** (4.38) ***
Total citations 0.013 0.003 0.001
(0.86) (0.18) (0.03)
Number of articles 0.033 0.037 0.077
[R.sup.2] (1.50) (1.80) * (4.47) ***
0.679 0.688 0.682
B. Omitting articles published in prior 3 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.100 0.120 0.096
(4.13) *** (4.87) *** (4.39) ***
Total citations 0.017 0.005 0.001
(1.07) (0.29) (0.04)
Number of articles 0.043 0.044 0.082
(1.79) * (1.99) ** (4.41) ***
[R.sup.2] 0.676 0.686 0.682
C. Omitting articles published in prior 6 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.102 0.117 0.090
(3.79) *** (4.28) *** (3.94) ***
Total citations 0.023 0.014 0.011
(1.52) (0.91) (0.71)
Number of articles 0.034 0.038 0.076
(1.24) (1.54) (3.59) ***
[R.sup.2] 0.649 0.658 0.652
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Results from Table 3A, including
articles published until end of 2010
Quality-adjusted journals 0.080 0.081 0.083
(4.27) *** (3.67) *** (4.79) ***
Total citations 0.015 0.021 0.014
(0.93) (1.27) (0.90)
Number of articles 0.068 0.060 0.077
[R.sup.2] (3.36) *** (2.84) *** (4.09) ***
0.673 0.670 0.678
B. Omitting articles published in prior 3 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.071 0.068 0.076
(3.74) *** (2.96) *** (4.21) ***
Total citations 0.018 0.024 0.016
(1.12) (1.42) (1.02)
Number of articles 0.077 0.072 0.083
(3.49) *** (3.07) *** (3.97) ***
[R.sup.2] 0.670 0.666 0.675
C. Omitting articles published in prior 6 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.065 0.062 0.063
(3.22) *** (2.60) ** (3.41) ***
Total citations 0.026 0.030 0.025
(1.61) (1.83) * (1.66) *
Number of articles 0.073 0.068 0.081
(2.96) *** (2.62) *** (3.40) ***
[R.sup.2] 0.641 0.637 0.642
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Results from Table 3A, including
articles published until end of 2010
Quality-adjusted journals 0.082 0.070 0.098
(4.71) *** (4.01) *** (4.05) ***
Total citations 0.014 0.014 -0.010
(0.93) (0.91) (0.51)
Number of articles 0.077 0.089 0.098
[R.sup.2] (4.09) *** (4.72) *** (5.74) ***
0.677 0.671 0.684
B. Omitting articles published in prior 3 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.074 0.071 0.092
(4.14) *** (4.17) *** (3.72) ***
Total citations 0.017 0.014 -0.008
(1.08) (0.96) (0.38)
Number of articles 0.084 0.092 0.104
(3.98) *** (4.54) *** (5.49) ***
[R.sup.2] 0.674 0.674 0.681
C. Omitting articles published in prior 6 years
(but citations for older articles counted to end of 2010)
Quality-adjusted journals 0.061 0.068 0.083
(3.36) *** (3.64) *** (3.38) ***
Total citations 0.026 0.021 0.006
(1.69) * (1.43) (0.33)
Number of articles 0.081 0.085 0.097
(3.41) *** (3.76) *** (4.50) ***
[R.sup.2] 0.642 0.645 0.650
Notes: Each regression also includes all of the other
variables from Table 2. N = 167, robust r-statistics
in parentheses.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
TABLE 6
Salary Regression Sensitivity Analyses that Consider
the Distribution of Citations
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Including total citations and citations to the most-cited article
Quality-adjusted journals 0.120 0.135 0.107
(4.58) *** (5.20) *** (4.60) ***
Number of articles 0.041 0.047 0.090
(1.85) * (2.38) ** (5.28) ***
Total citations -0.063 -0.083 -0.081
(1.42) (1.89) * (1.73) *
Citations to most-cited 0.068 0.076 0.072
(1.66) * (1.90) * (1.73) *
[R.sup.2] 0.682 0.692 0.686
Vuong non-nested test 3.09 *** 3.54 *** 3.41 ***
B. Including the h-indexfor citations
Quaiity-adjusted journals 0.097 0.112 0.085
(3.78) *** (4.56) *** (3.88) ***
Number of articles 0.019 0.027 0.061
(0.79) (1.17) (2.88) ***
Citations h-index 0.045 0.030 0.033
(1.36) (0.90) (0.97)
[R.sup.2] 0.681 0.689 0.684
Vuong non-nested test 1.47 2.07 ** 1.79 *
C. Including the generalized [h.sub.(5,2)]
index for citations
Quality-adjusted journals 0.102 0.115 0.089
(4.21) *** (4.76) *** (4.17) ***
Number of articles 0.035 0.038 0.076
(1.59) (1.90) * (4.56) ***
Citations [h.sub.(5,2)]-index 0.032 0.018 0.017
(1.26) (0.70) (0.61)
[R.sup.2] 0.682 0.689 0.683
Vuong non-nested test 2.84 *** 3.32 *** 3.21 ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Including total citations and citations to the most-cited article
Quality-adjusted journals 0.089 0.093 0.095
(4.43) *** (4.04) *** (4.84) ***
Number of articles 0.078 0.068 0.090
(3.66) *** (3.12) *** (4.69) ***
Total citations -0.053 -0.053 -0.073
(1.13) (1.16) (1.59)
Citations to most-cited 0.061 0.066 0.078
(1.44) (1.58) (1.85) *
[R.sup.2] 0.675 0.673 0.682
Vuong non-nested test 2.94 *** 2.63 *** 3.28 ***
B. Including the h-indexfor citations
Quaiity-adjusted journals 0.070 0.069 0.075
(3.75) *** (2.90) *** (4.26) ***
Number of articles 0.046 0.043 0.059
(1.89) * (1.72) * (2.53) **
Citations h-index 0.054 0.054 0.044
(1.65) (1.56) (1.36)
[R.sup.2] 0.676 0.673 0.680
Vuong non-nested test 1.22 0.98 1.59
C. Including the generalized [h.sub.(5,2)]
index for citations
Quality-adjusted journals 0.074 0.074 0.078
(4.03) *** (3.17) *** (4.50) ***
Number of articles 0.070 0.064 0.079
(3.55) *** (3.08) *** (4.32) ***
Citations [h.sub.(5,2)]-index 0.031 0.035 0.025
(1.18) (1.27) (0.92)
[R.sup.2] 0.675 0.672 0.679
Vuong non-nested test 2.78 *** 2.47 ** 3.09 ***
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Including total citations and citations to the most-cited article
Quality-adjusted journals 0.094 0.082 0.102
(4.77) *** (3.86) *** (4.08) ***
Number of articles 0.091 0.102 0.108
(4.66) *** (5.26) *** (5.94) ***
Total citations -0.073 -0.071 -0.061
(1.57) (1.31) (1.27)
Citations to most-cited 0.078 0.075 0.046
(1.85) * (1.60) (1.10)
[R.sup.2] 0.681 0.675 0.686
Vuong non-nested test 3.25 *** 2.92 *** 3.54 ***
B. Including the h-indexfor citations
Quaiity-adjusted journals 0.073 0.060 0.081
(4.19) *** (3.03) *** (3.84) ***
Number of articles 0.059 0.067 0.077
(2.52) ** (2.84) *** (3.35) ***
Citations h-index 0.045 0.051 0.036
(1.39) (1.42) (1.04)
[R.sup.2] 0.680 0.674 0.686
Vuong non-nested test 1.56 1.10 1.90 *
C. Including the generalized [h.sub.(5,2)]
index for citations
Quality-adjusted journals 0.077 0.064 0.084
(4.45) *** (3.33) *** (4.02) ***
Number of articles 0.079 0.090 0.093
(4.32) *** (5.00) *** (5.67) ***
Citations [h.sub.(5,2)]-index 0.025 0.024 0.020
(0.96) (0.84) (0.75)
[R.sup.2] 0.678 0.672 0.685
Vuong non-nested test 3.06 *** 2.76 *** 3.23 ***
Notes: Each regression has all of the other variables from Table 2.
N = 167, robust t-statistics in parentheses. The Vuong test is of
a model using citations variables versus a model using journals
variables (both having all control variables), with positive
values favoring the journals model.
* Significant at 10%; ** significant at 5%; *** significant at 1%.
TABLE 7
Salary Regressions using Lifetime Quality-Adjusted
Journal Output, Counts of Elite and Excellent
Journals, and Citations
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Using quality-, size- and coauthor-adjusted journal
pages, and journal tiers to measure journal output
Quality-adjusted journals 0.086 0.110 0.089
(2.71) *** (2.98) *** (2.38) **
Number of articles 0.033 0.032 0.058
(1.21) (1.21) (2.11) **
ln(total citations + 1) 0.094 0.088 0.096
(1.25) (1.16) (1.26)
ln(total citations + 1) (2) -0.046 -0.049 -0.053
(1.41) (1.55) (1.64)
# Elite articles 0.007 0.002 -0.001
(1.28) (0.27) (0.09)
# Excellent articles -0.001 -0.001 0.001
(0.20) (0.20) (0.17)
[R.sup.2] 0.689 0.694 0.689
F-test: tier-counts = 0 (a) 1.04 0.11 0.96
B. Using quality-, size- and coauthor-adjusted
journal pages to measure journal output
Quality-adjusted journals 0.097 0.113 0.088
(3.69) *** (4.30) *** (3.78) ***
Number of articles 0.022 0.026 0.062
(0.93) (1.16) (2.91) ***
ln(total citations + 1) 0.115 0.092 0.095
(1.57) (1.23) (1.26)
ln(total citations + 1) (2) -0.045 -0.049 -0.053
(1.38) (1.55) (1.68) *
[R.sup.2] 0.687 0.694 0.689
F-test: citations 1.44 1.33 1.55
effect = 0 (a)
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Using quality-, size- and coauthor-adjusted journal
pages, and journal tiers to measure journal output
Quality-adjusted journals 0.047 0.042 0.056
(1.80) * (1.49) (2.25) **
Number of articles 0.046 0.042 0.055
(1.67) * (1.53) (2.00) **
ln(total citations + 1) 0.101 0.094 0.095
(1.36) (1.21) (1.27)
ln(total citations + 1) (2) -0.043 -0.037 -0.041
(1.33) (1.16) (1.23)
# Elite articles 0.008 0.010 0.006
(1.35) (1.95) * (1.05)
# Excellent articles 0.002 0.002 0.002
(0.74) (0.87) (0.55)
[R.sup.2] 0.684 0.683 0.686
F-test: tier-counts = 0 (a) 0.93 1.98 0.58
B. Using quality-, size- and coauthor-adjusted
journal pages to measure journal output
Quality-adjusted journals 0.070 0.066 0.073
(3.48) *** (2.57) ** (3.95) ***
Number of articles 0.054 0.051 0.064
(2.31) ** (2.16) ** (2.80) ***
ln(total citations + 1) 0.121 0.123 0.109
(1.67) * (1.60) (1.48)
ln(total citations + 1) (2) -0.044 -0.034 -0.040
(1.38) (1.08) (1.23)
[R.sup.2] 0.681 0.677 0.685
F-test: citations 1.56 1.30 1.23
effect = 0 (a)
Journal Weighting Scheme for
Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Using quality-, size- and coauthor-adjusted journal
pages, and journal tiers to measure journal output
Quality-adjusted journals 0.054 0.027 0.090
(2.18) ** (0.82) (2.63) ***
Number of articles 0.054 0.056 0.067
(1.98) ** (1.99) ** (2.30) **
ln(total citations + 1) 0.096 0.103 0.095
(1.28) (1.36) (1.26)
ln(total citations + 1) (2) -0.041 -0.040 -0.071
(1.23) (1.21) (2.16) **
# Elite articles 0.006 0.009 0.001
(1.06) (1.12) (0.13)
# Excellent articles 0.002 0.003 0.002
(0.61) (0.96) (0.56)
[R.sup.2] 0.686 0.681 0.695
F-test: tier-counts = 0 (a) 0.56 0.75 0.85
B. Using quality-, size- and coauthor-adjusted
journal pages to measure journal output
Quality-adjusted journals 0.072 0.058 0.094
(3.91) *** (2.90) *** (3.77) ***
Number of articles 0.064 0.074 0.078
(2.81) *** (3.28) *** (3.53) ***
ln(total citations + 1) 0.111 0.113 0.098
(1.51) (1.48) (1.32)
ln(total citations + 1) (2) -0.040 -0.040 -0.074
(1.22) (1.19) (2.32) **
[R.sup.2] 0.684 0.678 0.694
F-test: citations 1.26 1.22 2.76 *
effect = 0 (a)
Notes: The dependent variable is log of 2010 academic
year salary and each model also includes all of the other
variables, which are not measures of research productivity
and impact, which are included in the models in Table 2. N = 167.
Robust t- statistics in parentheses. The # Elite articles counts
articles published by each academic in the American Economic
Review, the Journal of Political Economy, the Quarterly Journal
of Economics, Econometrica, and the Review of Economics and
Statistics. The # Excellent articles counts articles published
in the other 31 journals of Scott and Mitias (1996). The
quadratic in log citations and the counts of articles in
elite and excellent journals follow the specification
used in Table 6B by HRH (2015).
(a) This is an F-test for coefficients
(in Panel A on # Elite articles and # Excellent articles,
and in Panel B on the polynomial in log citations)
being jointly zero.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
TABLE 8
Estimated Effects of Citations with Different
Approaches to Controlling for Quality-Adjusted
Journals in the HRH Sample
Approach to Measuring Journal Output Comes from
HRH MSF CLm
Full sample (N = 1,009)
Incremental [R.sup.2] (a) 0.0375 0.0382 0.0320
% change from using -1.8% 17.2%
journal tiers (b)
Incremental salary (c) $28,944 $27,763 $25,855
% change from using 4.3% 11.9%
journal tiers (b)
Top-ranked departments NRC 2010 ranks 1-49 (N=485)
Incremental [R.sup.2] (a) 0.0281 0.0266 0.0188
% change from using 5.6% 49.5%
journal tiers (b)
Incremental salary (c) $29,065 $27,403 $23,402
% change from using 6.1% 24.2%
journal tiers (b)
Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Incremental [R.sup.2] (a) 0.0552 0.0564 0.0560
% change from using -2.1% -1.4%
journal tiers (b)
Incremental salary (c) $21,847 $20,631 $20,709
% change from using 5.9% 5.5%
journal tiers (b)
Approach to Measuring Journal Output Comes from
CLh RePEc Coupe
Full sample (N = 1,009)
Incremental [R.sup.2] (a) 0.0284 0.0318 0.0336
% change from using 32.0% 17.9% 11.6%
journal tiers (b)
Incremental salary (c) $24,749 $25,994 $26,794
% change from using 16.9% 11.3% 8.0%
journal tiers (b)
Top-ranked departments NRC 2010 ranks 1-49 (N=485)
Incremental [R.sup.2] (a) 0.0170 0.0206 0.0272
% change from using 65.3% 36.4% 3.3%
journal tiers (b)
Incremental salary (c) $22,540 $24,484 $27,979
% change from using 28.9% 18.7% 3.9%
journal tiers (b)
Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Incremental [R.sup.2] (a) 0.0545 0.0558 0.0528
% change from using 1.3% -1.1% 4.5%
journal tiers (b)
Incremental salary (c) $20,634 $20,763 $20,568
% change from using 5.9% 5.2% 6.2%
journal tiers (b)
Approach to Measuring Journal Output Comes from
K&Y_all K&Y_eco KMS LP
Full sample (N = 1,009)
Incremental [R.sup.2] (a) 0.0302 0.0303 0.0318 0.0269
% change from using 24.2% 23.8% 17.9% 39.4%
journal tiers (b)
Incremental salary (c) $25,458 $25,526 $26,196 $23,987
% change from using 13.7% 13.4% 10.5% 20.7%
journal tiers (b)
Top-ranked departments NRC 2010 ranks 1-49 (N=485)
Incremental [R.sup.2] (a) 0.0219 0.0216 0.0229 0.0177
% change from using 28.3% 30.1% 22.7% 58.8%
journal tiers (b)
Incremental salary (c) $25,209 $25,146 $26,394 $22,417
% change from using 15.3% 15.6% 10.1% 29.7%
journal tiers (b)
Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Incremental [R.sup.2] (a) 0.0541 0.0545 0.0543 0.0529
% change from using 2.0% 1.3% 1.7% 4.3%
journal tiers (b)
Incremental salary (c) $20,693 $20,736 $20,523 $20,501
% change from using 5.6% 5.4% 6.4% 6.6%
journal tiers (b)
Notes: The base model is that reported in column (5),
Table 6B of HRH (2015). That model for log salary of
1,009 economists from 53 different schools has as explanatory
variables: quadratics in experience, in the logarithm of lifetime
citations (plus one), and in seniority, dummy variables for males
and for each school, and counts of the number of articles published
in Elite, Excellent, and Other journals, where Elite and Excellent
are defined in Table 7. Models in the columns headed MSF though LP
control for quality-adjusted journal output of each economist by
using the number of size-, quality-, and coauthor adjusted journal
pages published in the career to the end of 2006 (using the type
of journal weight indicated by the column heading), and the count of
these articles, which is the same approach used in Tables 2 to 7 of
the current study.
(a) The increase in [R.sup.2] for each model when the logarithm
and squared logarithm of lifetime citations (plus one) are added
as explanatory variables.
(b) The percentage increase in either the incremental [R.sup.2]
or the incremental salary when the HRH approach to measuring
quality-adjusted journal output is used rather than using the
adjusted journal pages approach (based on the type of journal
weights indicated by the column heading).
(c) The predicted increase in salary from a standard deviation
increase in citations. Duan's (1983) smearing estimator is used,
given the log dependent variable.
TABLE 9
Comparison of Salary Determinants for Top-Ranked
Schools and Other Schools in the HRH Sample
Journal Weighting Scheme
for Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
MSF CLm CLh
A. Top-ranked departments NRC 2010 ranks 1-49 (N = 485)
Quality-adjusted journals 0.066 0.082 0.070
(3.18) *** (3.96) *** (3.59) ***
Number of articles 0.022 0.025 0.045
(0.99) (1.17) (2.17) **
ln(total citations + 1) 0.023 0.023 0.024
(1.36) (1.37) (1.41)
ln(total citations + 1) (2) 0.005 0.004 0.004
(2.09) ** (1.61) (1.43)
Experience 0.022 0.022 0.023
(3.60) *** (3.63) *** (3.82) ***
Experience (2) -0.000 -0.000 -0.000
(3.23) *** (3.27) *** (3.49) ***
Seniority -0.019 -0.018 -0.018
(4.05) *** (3.81) *** (3.80) ***
Seniority (2) 0.000 0.000 0.000
(2.70) *** (2.59) *** (2.57) **
Male 0.050 0.043 0.042
(1.95) * (1.74) * (1.70) *
[R.sup.2] 0.645 0.651 0.650
B. Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Quality-adjusted journals -0.013 -0.008 -0.004
(0.70) (0.45) (0.21)
Number of articles 0.076 0.071 0.068
(3.85) *** (3.85) *** (3.98) ***
ln(total citations + 1) 0.009 0.009 0.009
(0.63) (0.62) (0.63)
ln(total citations + 1) (2) 0.008 0.008 0.008
(3.23) *** (3.18) *** (3.09) ***
Experience 0.010 0.010 0.010
(2.22) ** (2.20) ** (2.16) **
Experience (2) -0.000 -0.000 -0.000
(0.70) (0.70) (0.67)
Seniority -0.019 -0.019 -0.019
(4.26) *** (4.24) *** (4.20) ***
Seniority (2) 0.000 0.000 0.000
(2.97) *** (2.95) *** (2.92) ***
Male -0.010 -0.010 -0.010
(0.53) (0.52) (0.52)
[R.sup.2] 0.662 0.662 0.662
F-test for pooling 3.27 *** 3.10 *** 2.71 ***
samples (a)
Journal Weighting Scheme
for Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
RePEc Coupe K&Y_all
A. Top-ranked departments NRC 2010 ranks 1-49 (N = 485)
Quality-adjusted journals 0.064 0.052 0.055
(3.39) *** (2.49) ** (3.17) ***
Number of articles 0.039 0.032 0.047
(1.87) * (1.39) (2.24) **
ln(total citations + 1) 0.026 0.025 0.027
(1.50) (1.43) (1.53)
ln(total citations + 1) (2) 0.004 0.005 0.004
(1.57) (2.04) ** (1.62)
Experience 0.023 0.023 0.023
(3.60) *** (3.67) *** (3.72) ***
Experience (2) -0.000 -0.000 -0.000
(3.15) *** (3.26) *** (3.32) ***
Seniority -0.019 -0.020 -0.019
(3.88) *** (4.10) *** (3.98) ***
Seniority (2) 0.000 0.000 0.000
(2.54) ** (2.71) *** (2.66) ***
Male 0.046 0.052 0.046
(1.84) * (2.05) ** (1.86) *
[R.sup.2] 0.647 0.642 0.645
B. Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Quality-adjusted journals -0.008 -0.002 -0.004
(0.49) (0.11) (0.25)
Number of articles 0.070 0.067 0.068
(4.07) *** (3.70) *** (4.00) ***
ln(total citations + 1) 0.009 0.010 0.009
(0.60) (0.64) (0.61)
ln(total citations + 1) (2) 0.008 0.008 0.008
(3.19) *** (3.02) *** (3.07) ***
Experience 0.010 0.010 0.010
(2.19) ** (2.15) ** (2.16) **
Experience (2) -0.000 -0.000 -0.000
(0.69) (0.68) (0.67)
Seniority -0.019 -0.019 -0.019
(4.23) *** (4.18) *** (4.21) ***
Seniority (2) 0.000 0.000 0.000
(2.93) *** (2.91) *** (2.93) ***
Male -0.010 -0.010 -0.010
(0.52) (0.53) (0.52)
[R.sup.2] 0.662 0.662 0.662
F-test for pooling 2 92 *** 2.71 *** 2.61 ***
samples (a)
Journal Weighting Scheme
for Calculating Quality-Adjusted
Journal Output over Lifetime
Comes from
K&Y_econ KMS LP
A. Top-ranked departments NRC 2010 ranks 1-49 (N = 485)
Quality-adjusted journals 0.055 0.047 0.065
(3.13) *** (2.63) *** (3.63) ***
Number of articles 0.047 0.050 0.054
(2.25) ** (2.39) ** (2.60) ***
ln(total citations + 1) 0.027 0.022 0.029
(1.53) (1.29) (1.67) *
ln(total citations + 1) (2) 0.004 0.005 0.003
(1.63) (1.96) * (1.20)
Experience 0.023 0.024 0.023
(3.71) *** (3.87) *** (3.74) ***
Experience (2) -0.000 -0.000 -0.000
(3.31) *** (3.54) *** (3.41) ***
Seniority -0.019 -0.019 -0.019
(3.97) *** (4.00) *** (3.98) ***
Seniority (2) 0.000 0.000 0.000
(2.65) *** (2.68) *** (2.71) ***
Male 0.046 0.046 0.041
(1.85) * (1.89) * (1.66) *
[R.sup.2] 0.645 0.644 0.649
B. Lower ranked departments NRC 2010 ranks 50-120 (N = 524)
Quality-adjusted journals -0.005 -0.001 -0.001
(0.31) (0.09) (0.05)
Number of articles 0.068 0.067 0.066
(4.03) *** (3.92) *** (3.85) ***
ln(total citations + 1) 0.009 0.010 0.010
(0.60) (0.65) (0.65)
ln(total citations + 1) (2) 0.008 0.008 0.008
(3.10) *** (3.08) *** (3.02) ***
Experience 0.010 0.010 0.010
(2.17) ** (2.14) ** (2.14) **
Experience (2) -0.000 -0.000 -0.000
(0.67) (0.67) (0.67)
Seniority -0.019 -0.019 -0.019
(4.21) *** (4.18) *** (4.18) ***
Seniority (2) 0.000 0.000 0.000
(2.93) *** (2.90) *** (2.89) ***
Male -0.010 -0.010 -0.010
(0.52) (0.52) (0.53)
[R.sup.2] 0.662 0.662 0.662
F-test for pooling 2.38 *** 2.52 *** 2.56 ***
samples (a)
Notes: The base model is that reported in column (5),
Table 6B of HRH (2015) for the log salary of 1,009 economists
in 53 schools. The journal quality measures and article counts
are used instead of the counts of articles in "elite,"
"excellent," and "other" journals used by HRH. The models
also include unreported fixed effects for each school.
Robust t-statistics in parentheses.
(a) This is an F-test for interaction terms on all
coefficients being jointly zero, with 9, and
938 degrees of freedom.
* Significant at 10%; ** significant at 5%;
*** significant at 1%.
COPYRIGHT 2017 Western Economic Association International
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.