摘要：Firms' decisions about which goods to produce are often made at a more
disaggregate level than the data observed by empirical researchers. When
products differ according to production technique or the way in which they enter
demand, this data aggregation problem introduces a bias into standard measures
of firm productivity. We develop a theoretical model of heterogeneous firms
endogenously self-selecting into heterogeneous products. We characterize the
bias introduced by unobserved variation in product mix across firms, and the
implications of this bias for identifying firm and industry responses to
exogenous policy shocks such as deregulation. More generally, we demonstrate
that product switching gives rise to a richer set of industry-level dynamics
than models where firm product mix remains fixed.
关键词：Product choice, Productivity, Deregulation, Industry Evolution
