Analyzing data on all U.S. employers in a cohort of entering firms, we document a highly skewed size distribution, such that the largest 5% account for over half of cohort employment at firm birth and more than two-thirds at firm age 7. Little of the size variation is accounted for by industry...

Continuous Gibrat#x2019;s Law and Gabaix#x2019;s Derivation of Zipf#x2019;s Law -- Flow of Firm Creation -- Useful Properties of Realizations of the Geometric Brownian Motion -- Exit or #x201C;Death#x201D; of Firms -- Deviations from Gibrat#x2019;s Law and Implications for Generalized Zipf#x2019;s Laws -- Firm#x2019;s Sudden...