Several structural results for the set of competitive equilibria in trading networks with frictions are established: The lattice theorem, the rural hospitals theorem, the existence of side-optimal equilibria, and a group-incentive-compatibility result hold without the assumption of quasi-linear...

Online platforms that match customers with service providers utilize a wide variety of designs: some implement a searchable directory of one side of the market (i.e., Airbnb, Google Local Services); some allow both sides of the market to search and initiate contact (i.e., Upwork, Care.com);...

We study many-to-one matching markets in a dynamic framework with the following features: Matching is irreversible, participants exogenously join the market over time, each agent is restricted by a quota, and agents are perfectly patient. A form of strategic behavior in such markets emerges: The...

Recently dozens of school districts and college admissions systems around the world have reformed their admission rules. As a main motivation for these reforms the policymakers cited strategic flaws of the rules: students had strong incentives to game the system, which caused dramatic...

We examine two-sided markets where players arrive stochastically over time and are drawn from a continuum of types. The cost of matching a client and provider varies, so a social planner is faced with two contending objectives: a) to reduce players' waiting time before getting matched; and b) to...

We investigate menu mechanisms: dynamic mechanisms where at each history, an agent selects from a menu of his possible assignments. We consider both ex-post implementation and full implementation, for both subgame perfection and a strengthening of dominance that covers off-path histories, and...

As a random allocation rule for indivisible object allocation problems under weak priorities, deferred acceptance with single tie-breaking (DA-STB) is not ex-post constrained efficient. We first observe that it also fails to satisfy a natural fairness notion, symmetry at the top, which requires...

I investigate three goals of school choice: student welfare, encouraging neighborhood schools, and diversity. I develop a framework for finding the optimal match for any combination of these objectives while respecting stability and incentive compatibility. I then apply my framework to data from...

Despite significant efforts, segregation in the US public schools still persists. It mainly occurs between, but not within, school districts. To overcome this problem, inter-district admissions have been introduced, and many school districts have been integrated in a handful of states. We study...

The Chicago Board of Education is implementing a centralized clearinghouse to assign students to schools for 2018-19 admissions. In this clearinghouse, each student can simultaneously be admitted to a selective and a nonselective school. We study this divided enrollment system and show that an...