Industrial dynamics, Gibrat's Law, Firm Growth, Aggregation.

L1, C1, D2

We report several characteristics of industrial dynamics, including the firm size distribution, Gibrat's Law, and also the distribution of growth rates and their autocorrelation. We use a variety of econometric techniques, looking first at the aggregate and subsequently at a sectoral level. Many of our results corroborate previous findings, but there are also several surprises. For example, although previous findings on US and Italian data find that the growth rate distribution follows the Laplace density (i.e. is 'tent-shaped'), the French growth rates distribution has noticeably fatter tails. Growth rates depend negatively on size but the relationship does not seem to be linear, with larger firms possibly growing faster than medium-sized ones. It also appears that growth rate autocorrelation may vary with firm size: autocorrelation is negative for smaller firms, but the magnitude seems to decrease with size and becomes positive for larger firms.