Before revision:  We analyze this constrained price discrimination problem, and apply our insights to two distinct two-sided market models: one in which the platform chooses prices and  sellers choose quantities (similar to ride-sharing), and one in which  sellers choose prices (similar to e-commerce).
After revision:  We analyze this constrained price discrimination problem, and apply our insights to two distinct two-sided market models: one in which the platform chooses prices and the sellers choose quantities (similar to ride-sharing), and one in which sellers choose prices (similar to e-commerce).