Seminario CEA-MIPP - Miercoles 03/09/2025, 12:30 HRS - Sala de Consejo, piso 4, Beauchef 851 - "The Case for Multiple Tie-Breaking Rules" - Sumeyra Akin (PUC)

Tema: «The Case for Multiple Tie-Breaking Rules«

Presenta: Sumeyra Akin (PUC)

Centralized school assignment systems typically rely on the deferred acceptance mechanism, where coarse school priorities necessitate tie-breaking rules. Two prominent approaches are the single tie-breaking rule (STB), which uses a single lottery across all schools, and the multiple tie-breaking rule (MTB), which assigns independent lotteries to each school. While STB can yield more top-choice assignments, it also exposes students to extreme luck-based outcomes. In contrast, MTB distributes these risks more evenly, but at the cost of fewer first-choice matches. This paper develops a finite matching model with aligned student preferences to provide a theoretical perspective on policymakers’ preference for MTB. We show that the distribution of rejections under MTB is both lower and less dispersed than under STB, a property that makes MTB more attractive to a risk-averse planner. Our results complement existing empirical and theoretical findings by clarifying when and why MTB may be the more equitable choice in school assignment design.