Günnur Ege Bilgin

Working Papers

• Decentralized Many-to-One Matching with Random Search (JMP)
  I analyze a canonical many-to-one matching market within a decentralized search model with frictions, where a finite number of firms and workers meet randomly until the market clears. I compare the stable matchings of the underlying market and equilibrium outcomes when time is nearly costless. In contrast to the case where each firm has just a single vacancy, I show that stable matchings are not obtained as easily. In particular, there may be no Markovian equilibrium that uniformly implements either the worker- or the firm-optimal stable matching in every subgame. The challenge results from the firms' ability to withhold capacity strategically. Yet, this is not the case for markets with vertical preferences on one side, and I construct the equilibrium strategy profile that leads to the unique stable matching almost surely. Moreover, multiple vacancies enable firms to implicitly collude and achieve unstable but firm-preferred matchings, even under Markovian equilibria. Finally, I identify one sufficient condition on preferences to rule out such opportunities.

• Placement with Assignment Guarantees and Semi-Flexible Capacities (joint with Orhan Aygün)
  We analyze an extension of the many-to-one placement problem, where some doctors are exogenously guaranteed a seat at a program, which defines a lower bound on their assignment. Respecting assignment guarantees, combined with the limited capacities of programs often violates fairness and leaves more preferred doctors unemployed. Pursuing fairness, a designer often has to deviate from the target capacities of programs. In order to prevent excessive deviations, we introduce two notions that are tailored to the environment: q-fairness and avoiding unnecessary slots. We present the Assignment-Guarantees-Adjusted Mechanism (AGAM) and show that it is the unique strategy-proof mechanism that satisfies q-fairness and avoids unnecessary slots whilst respecting assignment guarantees. Furthermore, among the mechanisms that are q-fair and respect guarantees, AGAM minimizes the deviation from the target capacities.
  
  

• Preserving Acquired Rights in the Re-placement of Medical Residents in Turkey (joint with Orhan Aygün)
  We analyze the re-placement mechanism implemented in Turkey for reassigning doctors to residency programs in Turkey after scoring errors were realized, an issue that occurred thrice in the past decade. Legally, initial placements based on faulty scores are considered acquired rights, preventing any re-placement to less favorable programs. This setup necessitates a balance between restoring fairness for those with improved ranking and preserving the acquired rights while also adhering to predetermined program capacities as much as possible. Our analysis focuses on the two-step serial dictatorship mechanism utilized by the Center for Assessment, Selection, and Placement to address this challenge. We demonstrate that the mechanism violates fairness, such that doctors with higher scores may justifiably envy the assignments of others with lower scores. Yet, it does comply with a modified, more lenient notion of q-fairness, aligning better with scenarios involving acquired rights. Additionally, we show the manipulation incentives by the doctors. Finally, we propose an alternative mechanism to reduce deviations from the target program capacities and describe alterations to the existing mechanism, which would make the two mechanisms equivalent.

• Voting under Salience Bias and Strategic Extremism (joint with Cavit Görkem Destan)
  We present a model that demonstrates politicians strategically adopt extreme positions even when the voters are homogeneous and moderate. We examine the behavior of voters and electoral candidates under the assumption that the salience of political issues affects voting decisions through voter preferences. Voters have limited attention which is unintentionally captured by distinctive policies. We demonstrate that candidates who differ in their budget constraints along with voters who have such limited attention can account for extremist policies, even though voters are identical in their preferences. Subsequently, we examine the elections with decoy candidates, who are unlikely to win. Even though these candidates do not attract the voters, they might still influence the election outcome by altering salience. Moreover, we provide experimental evidence that salience affects consumer preferences and election outcomes.

• Fall 2024: Graduate Microeconomics (Microeconomics I) at TEDU

• Fall 2024: Matching Theory and Market Design at TEDU

• Summer 2021,2022,2024: EC 101 - Introduction to Microeconomics at Bogazici University