Testable implications for the Bresnahan-Lau model of market competition

We derive necessary and sufficient testable implications on the reduced form price and quantity functions for the Bresnahan-Lau model of market competition. The conditions are twofold. A first condition relates to the fact that the reduced form price function should correspond to an inverse demand function. The second condition captures that the degree of competition must be invariant to changes in the exogenous variables.