Platform Pricing at Sports Card Conventions

We study a new data set of US sports card conventions in order to evaluate the pricing theory of two-sided markets. Conventions are two-sided because organizers must set fees to attract both consumers and dealers. We have detailed information on consumer price, dealer price and, since most conventions are local, the market structure for conventions. We present several findings: first, consumer pricing decreases with competition at any reasonable distance, but pricing to dealers is insensitive to competition and in longer distances even increases with competition. Second, when consumer price is zero (and thus constrained), dealer price decreases more strongly with competition. These results are compatible with existing models of two-sided markets, but are difficult to explain without such models