Abstract
Low-cost airlines in Mexico affect the lowest-quoted fares of one of the two principal incumbent carriers, but have no effect on the lowest-quoted fares of the other incumbent carrier. The same conclusion holds for competition between incumbent carriers where the lowest-quoted fares of one of the incumbent carriers is lower when incumbents compete. Congestion at the Mexico City airport is limiting potential competition, with carriers being able to charge a significant price premium. This suggests that the societal costs of airport congestion can go well beyond the negative congestion externality and should also include the effects of reduced competition. These findings raise important public policy issues.