Platforms often use fee discrimination within their marketplace (e.g., Amazon, eBay, and Uber specify a variety of merchant fees). To better understand the impact of marketplace fee discrimination, we develop a model that allows us to determine equilibrium fee and category decisions that depend...

We analyze the competitive effects of backward vertical integration by a partially vertically integrated firm that competes with non-integrated firms both upstream and downstream. We show that vertical integration is procompetitive under fairly general conditions. It can be anticompetitive only...