This paper examines how a profit-maximizing monopolist competes against a free but capacity-constrained public option. The monopolist strategically restricts its supply beyond standard monopoly levels, thereby intensifying congestion at the public option and increasing consumers' willingness to pay for guaranteed access. Expanding the capacity of the public option always reduces producer welfare and, counterintuitively, may also reduce consumer welfare. In contrast, introducing a monopolist to a market served only by a capacity-constrained public option unambiguously improves consumer welfare. These findings have implications for mixed public-private markets, such as healthcare, education, and housing.

An agent engages in sequential search and learns about the quality of sampled goods by purchasing signals from profit-maximizing information brokers. We study how market structure—the number of competing brokers—affects the pricing and design of information and the resulting welfare outcomes. We characterize the equilibrium payoff set and show that when search costs are low, market structure affects neither surplus generation nor its division. When costs are high, however, competition expands the equilibrium set in ways that raise the agent’s payoff but reduce total surplus relative to monopoly. Methodologically, we extend repeated-games theory to stopping problems such as sequential search.

We use majorization to model comparative diversity in school choice. A population of agents is more diverse than another population of agents if its distribution over groups is less concentrated: being less concentrated takes a specific mathematical meaning borrowed from the theory of majorization. We adapt the standard notion of majorization in order to favor arbitrary distributional objectives, such as population-level distributions over race/ethnicity or socioeconomic status. With school admissions in mind, we axiomatically characterize choice rules that are consistent with modified majorization, and constitute a principled method for admitting a diverse population of students into a school. Two important advantages of our approach is that majorization provides a natural notion of diversity, and that our axioms are independent of any exogenous priority ordering. We compare our choice rule to the leading proposal in the literature, ``reserves and quotas,'' and find ours to be more flexible.

I study a continuous time principal-agent model in which an unknown parameter and the agent's hidden effort affect the distribution of observable outcomes. The principal and the agent learn about the parameter by observing past outcomes. The agent's current effort has an implicit long-term effect through the belief dynamics and a deviation in effort creates a persistent disparity between the principal's and the agent's beliefs. This disparity affects the rate of learning as well as how the two evaluate the expected distribution of future outcomes which in turn affects their evaluation of future payoffs. Placing minimal restrictions on how effort and the parameter interact, I derive necessary and sufficient conditions for incentive compatible contracts. In addition to the agent's promised utility, the covariance between the on-path posterior beliefs and the agent's total payoff serves as a second state variable capturing the marginal long-run effects of effort.

This paper studies how ex-ante information affects consumer welfare in a search market where buyers search and match to sellers of a vertically differentiated product. In a random search market, a buyer gets no informative signal about the quality of a seller's product prior to matching, whereas in a directed search market, a buyer observes a perfectly informative signal. I derive the unique equilibrium outcome in each type of market and show that consumers are worse off in a directed search market when sellers are scarce and prices are bilaterally ex-post efficient.