Abstract:In many industries, the largest firms are most successful in entering and competing in individual markets or submarkets. While this success is often attributed to cost or quality differences, it may also reflect reputation advantages or marketing strategies that benefit firms selling a wider variety of products in the industry. I present an approach to estimating the advantages of a dominant firm in the airline industry that allows one to effectively control for cost and quality heterogeneity. Results using data from 1986 indicate that an airline with a dominant presence at an airport will have a significant advantage in attracting customers whose trips originate at that airport, regardless of the specific route on which the customer is traveling.