Nonlinearities in the Impact of Industry Structure: the Case of Concentration and Intra-industry Variability in Rates in Return.

This paper addresses the issue of industry concentration and intra-industry variability in rates of return. An inverted 'U' relationship is hypothesized and tested in which one observes low levels of variability both at high and low levels of concentration, in one case as a result of collusion and the other as a result of competition. In the process, the paper highlights the benefits associated with combining both industry and firm levels of analyses. [ABSTRACT FROM AUTHOR]