Deferred acceptance assignment with strategy-proof ranking¶

Theory · All theories
Evidence · 4 claims (4 for) · 2 studies (2 associational), q2 · 0 of 2 report an effect size · 4 claims rest on one study

Description¶

GoCPS assigns students via a deferred acceptance process: each student is temporarily placed in their top-ranked program, programs order eligible applicants by priority group and then lottery number or application score, seats are filled down the ordering, and unassigned students defer to their next-ranked program iteratively. The paper attributes two desirable properties to this process: it is "a stable assignment because no student loses a seat at a (preferred) program to a student who is ordered below them," and "the best option for students is to rank programs in their true preference ordering," removing any incentive for strategic ranking behavior. The same mechanism underlies medical resident hospital matching.

Design Implications¶

Context¶

Requirements¶

• Programs must have defined seat counts, priority groups, and selection rules (lottery or points) that the computerized process can apply
• Applicants submit ranked preference lists that the iterative process can process

Constraints¶

• The strategy-proofness property relies on students being allowed to order all available programs; GoCPS caps rankings at 20, which the authors argue is not problematic because most students rank fewer

Target Learners¶

• Incoming ninth-grade students participating in school choice

Target Learning Objectives¶

• Fair and stable assignment of students to requested programs
• Reducing strategic complexity in families' application decisions

Claims¶

• Gocps Points Admission Score Order [+M]
• Lottery-based selection under GoCPS worked as intended: lottery numbers and offers were unrelated to student characteristics and to how highly applicants ranked programs [+W]
• Most GoCPS applicants received an offer from a program they ranked: 93 percent in round 1 (51 percent at their top choice) and 85 percent in round 2 (61 percent at their top choice) [+W]
• Most GoCPS applicants received an offer from a preferred program: 51 percent from their top-ranked and 81 percent from a top-three ranked choice program [+W]

Related Theories¶

• Deferred acceptance with a single best offer

Examples¶

• GoCPS centralized application and single-best-offer platform

Key Sources¶

• Lisa Barrow, Lauren Sartain, & Marisa de la Torre. (2018). GoCPS: A First Look at Applications and Offers. https://consortium.uchicago.edu/publications/gocps-first-look-applications-and-offers