摘要：We study political dynasties in the United States Congress since its inception in
1789. We document patterns in the evolution and pro.le of political dynasties, study
the self-perpetuation of political elites, and analyze the connection between political
dynasties and political competition. We .nd that the percentage of dynastic legisla-
tors is decreasing over time and that dynastic legislators have been signi.cantly more
prevalent in the South, the Senate and the Democratic party. While regional and party
di¡èerences have largely disappeared over time, the di¡èerence across chambers has not.
We document di¡èerences and similarities in the pro.le and political careers of dynastic
politicians relative to the rest of legislators. We also .nd that legislators that enjoy
longer tenures are signi.cantly more likely to have relatives entering Congress later.
Using instrumental variables methods, we establish that this relationship is causal: a
longer period in power increases the chance that a person may start (or continue) a
political dynasty. Therefore, dynastic political power is self-perpetuating in that a
positive exogenous shock to a person.s political power has persistent e¡èects through
posterior dynastic attainment. Finally, we .nd that increases in political competition
are associated with fewer dynastic legislators, suggesting that dynastic politicians may
be less valued by voters.
关键词：Political elites, dynasties, self-perpetuation, political selection, legisla-
tures.
