Working Papers
Market Design of College-Major Switches for Reducing Student-Major Mismatch (with Umut Dur and Yi-Cheng Kao) - Job Market Paper (presentation of JMP)
It is not unusual for students to feel that their major is not a good fit for them. When such a mismatch between students and majors occurs, demand for major switching emerges. In practice, the number of major switches is usually constrained by the total number of initially vacant seats at each major. This constraint limits the number of successful major switches, preventing potential welfare gains for students. We propose new class of mechanisms to address the problem and demonstrate how these mechanisms could increase the success rate of major switching using data provided by the National Taiwan University (NTU). With the help of our early findings, in 2022, NTU adopted one of our proposed mechanisms.
Seattle Public Schools has had an interesting relationship with school choice mechanisms. The district once replaced the Boston mechanism with the Deferred Acceptance algorithm only to reverse the decision a decade later. Although the current mechanism has similarities with the Boston mechanism, it has its own unique features. We document that the mechanism in use differs from the Boston mechanism due to initial assignments of students to schools based on their home address. We discuss their motivation for this modification: an effort to provide a sense of ``predictability" to families in terms of their school assignments. We define a notion capturing this desire for predictability and show that the mechanism being used in Seattle to achieve this goal is leading to unnecessary efficiency losses. We provide an alternative mechanism, the Secure Seattle mechanism, and show that it Pareto dominates the current mechanism while also yielding the desired predictability. Further, we show that the proposed mechanism does not perform worse than the current mechanism in terms of vulnerability to manipulation or fairness. Our results demonstrate that replacing the current mechanism in use in Seattle with our proposed mechanism would be an unambiguous improvement for the students.
A Characterization of the Top Trading Cycles Mechanism for the School Choice Problem (with Umut Dur) revise and resubmit Mathematical Social Sciences
This paper characterizes the Top Trading Cycles (TTC) mechanism for the school choice problem where schools may have multiple available seats to be assigned to students. We first define weaker forms of fairness, consistency and resource monotonicity. We show that the TTC mechanism is the unique Pareto efficient and strategy-proof mechanism that satisfies these weaker forms of fairness, consistency and resource monotonicity. We also show that in a well-defined sense TTC is the "most stable'' Pareto efficient mechanism.
Works in Progress
Top Trading Cycles with Reserves (with SunAh An)