Dr. Emek Basker, Dissertation Supervisor.Includes vita.Field of study: Economics."July 2018."This dissertation consists of three chapters. The first chapter examines price dispersion in retail gasoline and focuses on differentiation along the service dimension: full service versus self service. Consistent with more intensive search by self-service customers, I find that price dispersion always decreases with the number of nearby self-service stations, but does not decrease with the number of nearby full-service stations. When I segment the market by brand, I observe that the estimates are sensitive to how brands are separated into different types. These findings show that the market is more clearly segmented by service level than by brand t...