​​Working Papers

When does an additional stage improve welfare in centralized assignment? (w/ M. B. Yenmez). [ssrn] [repec]
We study multistage centralized assignments to allocate scarce resources based on priorities in the context of school choice. We characterize the capacity-priority profiles of schools under which an additional stage of assignment may improve student welfare when the deferred acceptance algorithm is used at each stage. If the capacity-priority profile is acyclic, then no student prefers any subgame-perfect Nash equilibrium (SPNE) outcome of the 2-stage enrollment system to the truthful equilibrium outcome of the 1-stage enrollment system. If the capacity-priority profile is not acyclic, then an SPNE outcome of the 2-stage enrollment system may Pareto dominate the truthful equilibrium outcome of the 1-stage enrollment system.
Lexicographic choice under variable capacity constraints (w/ S. Dogan and K. Yildiz). [ssrn]
Journal of Public Economic Theory, revision requested.
In several matching markets, in order to achieve diversity, agents' priorities are allowed to vary across an institution’s available seats, and the institution is let to choose agents in a lexicographic fashion based on a predetermined ordering of the seats, called a lexicographic choice rule. Lexicographic choice rules have been particularly useful in achieving diversity at schools while allocating school seats. We provide a characterization of lexicographic choice rules, which reveals their distinguishing properties from other plausible choice rules. Moreover, we study the market design implications of using lexicographic choice rules and provide a characterization of deferred acceptance mechanisms that operate based on a lexicographic choice structure. We also discuss some implications for the Boston school choice system and show that our analysis can be helpful in applications to select among plausible choice rules. 
On capacity-filling and substitutable choice rules (w/ S. Dogan and K. Yildiz). [ssrn]
Mathematics of Operations Research, revision requested.
Each capacity-filling and substitutable choice rule is known to have a maximizer-collecting representation: there exists a list of priority orderings such that from each choice set that includes more elements than the capacity, the choice is the union of the priority orderings’ maximizers (Aizerman and Malishevski, 1981). We introduce the notion of a critical set and constructively prove that the number of critical sets for a choice rule determines its smallest size maximizer-collecting representation. We show that responsive choice rules require the maximal number of priority orderings in their smallest size maximizer-collecting representations among all capacity-filling and substitutable choice rules. We also analyze maximizer-collecting choice rules in which the number of priority orderings equals the capacity. We show that if the capacity is greater than three and the number of elements exceeds the ca- pacity by at least two, then no capacity-filling and substitutable choice rule has a maximizer-collecting representation of the size equal to the capacity.

Forthcoming and Published Papers

Consistent Pareto improvement over the student-optimal stable mechanism (w/ M. B. Yenmez). [ssrn] [publisher]
Economic Theory Bulletin, forthcoming.
Unified versus divided enrollment in school choice: improving student welfare in Chicago (w/ M. B. Yenmez). [ssrn] [repec] [publisher]
Games and Economic Behavior, 118, 366-373, 2019.
Object allocation via immediate acceptance: characterizations and an affirmative action application (w/ B. Klaus). [repec] [publisher]
Journal of Mathematical Economics, 79, 140-156, 2018.
A new ex-ante efficiency criterion and implications for the probabilistic serial mechanism (w/ S. Dogan and K. Yildiz). [ssrn] [publisher]
Journal of Economic Theory, 175, 178-200, 2018.
Eliciting the socially optimal allocation from responsible agents. [ssrn] [publisher]
Journal of Mathematical Economics, 73, 103-110, 2017.
Stability and the immediate acceptance rule when school priorities are weak (w/ W. J. Cho). [ssrn] [publisher]
International Journal of Game Theory, 46, 991-1014, 2017.
​​How to control controlled school choice: comment [ssrn] [repec] [publisher]
American Economic Review, 107, 1362-64, 2017.
Responsive affirmative action in school choice. [ssrn] [repec] [publisher]
Journal of Economic Theory, 165, 69-105, 2016.​
Nash-implementation of the no-envy solution on symmetric domains of economies. [ssrn] [publisher]
Games and Economic Behavior, 98, 165-171, 2016.
​Equivalence of efficiency notions for ordinal assignment problems (w/ W. J. Cho). [ssrn] [publisher] [online appendix]
Economics Letters, 46, 8-12, 2016.
Efficiency and stability of probabilistic assignments in marriage problems (w/ K. Yildiz). [ssrn] [publisher] 
Games and Economic Behavior, 95, 47-58, 2016.
Maskin-monotonic scoring rules (w/ S. Koray). [publisher] 
Social Choice and Welfare, 44, 423-432, 2015.