Industries with significant scale economies or learning-by-doing may come to be dominated by a single firm. Economists have studied how likely this is to happen, and whether it is efficient, using models where buyers are price or quantity takers, even though these industries are often also...

We develop a quantitative theory of prices in firm-to-firm trade with bilateral negotiations and two-sided market power. Markups reflect oligopoly and oligopsony forces, with relative bargaining power as weight. Cost pass-through elasticities into import prices can be incomplete or complete,...

In this note, we consider a broad class of network models where a large number of heterogeneous agents simultaneously interact in many ways. We provide an iterative algorithm for calculating an equilibrium and offer sufficient and "globally necessary" conditions under which the equilibrium is...

This paper studies how interest groups allocate campaign contributions when congressmen are connected by social ties. We establish conditions for the existence of a unique Nash equilibrium in pure strategies for the contribution game and characterize the associated allocation of the interest...

This paper provides the first quantitative economic models of pharmacy benefit management regulation. The price-theoretic models allow for various market frictions and imperfections including market power, coordination costs, tax distortions, and incomplete innovation incentives. A rigorous...

In theory, equilibrium profits for drug patent holders would not involve significant restraints on production and patient utilization if the market had a mechanism for two-part pricing (Oi 1971) or quantity commitments (Murphy, Snyder, and Topel 2014). In fact, patent expiration has little...

Proposed "delinking" legislation would prohibit Pharmacy Benefit Managers (PBMs) from being remunerated based on the rebates and discounts they negotiate for drug insurance plans serving Medicare beneficiaries. This policy would significantly change drug pricing and utilization and shift...

We study a model of social learning and communication using hard anecdotal evidence. There are two Bayesian agents (a sender and a receiver) who wish to communicate. The receiver must take an action whose payoff depends on their personal preferences and an unknown state of the world. The sender...

We propose a new model of legislative bargaining in which coalitions have different values, reflecting the fact that the policies they can pursue are constrained by the identity of the coalition members. In the model, a formateur picks a coalition and negotiates for the allocation of the surplus...

A central authority possessing tax and expenditure responsibilities can readily provide an efficient level of a public good. Absent a central authority, voluntary arrangements must replace coercive ones. Significant under-provision must be expected. International public goods are particularly...