A Stable and Strategy-Proof Controlled School Choice Mechanism with Integrated and Flexible Rules

Abstract: We examine a controlled school choice model where students are categorized into different types, and the distribution of these types within a school influences its priority structure. This study provides a general framework that integrates existing controlled school choice models, including those utilizing reserve rules, quota rules, and bonus-point rules. Specifically, we introduce an adjusted scoring rule that unifies these rules. By achieving a matching that satisfies the stability defined in this framework, matching authorities can effectively manage the trade-offs inherent in controlled school choice markets. Moreover, the priority order for a school is represented as a weak order with each given assignment, meaning that ties are allowed. Our mechanism ensures a stable matching and satisfies strategy-proofness. In particular, when priority orders are restricted to linear orders with each given assignment, our mechanism guarantees student-optimal stability.