Standard policies to correct market power and selection can be misguided when these two forces co-exist. Using a calibrated model of employer-sponsored health insurance, we show that the risk adjustment commonly used by employers to offset adverse selection often reduces the amount of...

Many models of monopoly in two-sided markets have been proposed (Rochet and Tirole, 2006), but little is known about them. I provide a full set of comparative statics for three models, one that generalizes that of Rochet and Tirole (2003), a second that generalizes Armstrong (2006) and a third...

One of the most salient issues faced by platforms like newspapers and credit card issuers is that users are heterogeneous in the value they bring to other users or to the platform. We develop a model with multi-dimensional heterogeneity where a monopoly platform chooses (price or non-price)...

This paper builds on contributions to the Sloan conference Benefit-Cost Analysis of Financial Regulation, held at the University of Chicago, to show how benefit-cost analysis (BCA) of financial regulations should be conducted. Our major themes are that (1) on theoretical grounds, BCA should be...

Rochet and Tirole [Rochet, J.-C., Tirole, J., 2003. Platform competition in two-sided markets. Journal of the European Economic Association 1(4), 990-1029] consider the consumer Ramsey problem in a model of two-sided markets. I extend their analysis to the social Ramsey and Lindahl problems,...

Holdout problems prevent private (voluntary and self-financing) assembly of complementary goods--such as land or dispersed spectrum--from many self-interested sellers. While mechanisms that fully respect sellers' property rights cannot alleviate these holdout problems, traditional solutions,...

I develop a general theory of monopoly pricing of networks. Platforms use insulating tariffs to avoid coordination failure, implementing any desired allocation. Profit maximization distorts in the spirit of A. Michael Spence (1975) by internalizing only network externalities to marginal users....

The externalities advertisers receive from newspaper readers and that operating system users receive from software developers are among the leading features of those “platform” industries. However, they are rarely incorporated into applied models of imperfect competition. We argue this...

We extend five principles of tax incidence under perfect competition to a general model of imperfect competition. The principles cover (1) the independence of physical and economic incidence, the (2) qualitative and (3) quantitative manner in which taxes are split between consumers and...

Using information local to the premerger equilibrium, we derive approximations of the expected changes in prices and welfare generated by a merger. We extend the pricing pressure approach of recent work to allow for non-Bertrand conduct, adjusting the diversion ratio and incorporating the change...