This volume collects a series of essays that I have written over the last decade on multi-sided platform businesses that create value by providing products that enable two or more different types of customers to get together, find each other, and exchange value. Part I presents background pieces...

A planner sets a lump sum transfer and a linear tax on labor income in an economy with incomplete markets, heterogeneous agents, and aggregate shocks. The planner's concerns about redistribution impart a welfare cost to fluctuating transfers. The distribution of net asset holdings across agents...