Mechanisms according to which private intermediaries or governments charge transaction fees or indirect taxes are prevalent in practice. We consider a setup with multiple buyers and sellers and two-sided independent private information about valuations. We show that any weighted average of...

In many markets, user benefits depend on participation and usage decisions of other users giving rise to network effects. Intermediaries manage these network effects and thus act as platforms that bring users together. This paper reviews key findings from the literature on network effects and...

For many products, platforms enable sellers to transact with buyers. We show that the competitive conditions among sellers shape the market structure in platform industries. If product market competition is tough, sellers avoid competitors by joining different platforms. This allows platforms to...

Capturing financial network linkages and contagion in stress test models are important goals for banking supervisors and central banks responsible for micro- and macroprudential policy. However, granular data on financial networks is often lacking, and instead the networks must be reconstructed...

We analyze changes in unemployment, marginal labor force attachment and participation in Canada and the U.S. Using two complementary decompositions, we show the importance for the comparative evolution of aggregate unemployment of changes in the fraction of the non-employed who are unemployed...