When major investors own shares in several firms in the same industry, the traditional approach to concentration measurement by the Hirschman--Herfindahl Index (HHI) fails to accurately reflect the level of competition in the market. To address this problem we derive a generalized HHI formula...

Trujillo, Martín, Estache, and Campos provide empirical evidence on the impact that private participation in infrastructure has had on key macroeconomic variables in a sample of 21 Latin American countries from 1985–98. Specifically, they look at the effects on GDP per capita, current public...