Working Paper: NBER ID: w16783
Authors: Parag A. Pathak; Tayfun Sönmez
Abstract: In Fall 2009, officials from Chicago Public Schools changed their assignment mechanism for coveted spots at selective college preparatory high schools midstream. After asking about 14,000 applicants to submit their preferences for schools under one mechanism, the district asked them re-submit their preferences under a new mechanism. Officials were concerned that "high-scoring kids were being rejected simply because of the order in which they listed their college prep preferences" under the abandoned mechanism. What is somewhat puzzling is that the new mechanism is also manipulable. This paper introduces a method to compare mechanisms based on their vulnerability to manipulation. Under our notion, the old mechanism is more manipulable than the new Chicago mechanism. Indeed, the old Chicago mechanism is at least as manipulable as any other plausible mechanism. A number of similar transitions between mechanisms took place in England after the widely popular Boston mechanism was ruled illegal in 2007. Our approach provides support for these and other recent policy changes involving matching mechanisms.
Keywords: school admissions; manipulation; Chicago; England; mechanisms
JEL Codes: C78; I20
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| old Chicago mechanism (Chik) (E11) | new mechanism (Sdk) (O36) |
| old Chicago mechanism (Chik) (E11) | student assignments (Y40) |
| mechanism design (D47) | student outcomes (A21) |
| old Chicago mechanism (Chik) (E11) | preference manipulation (D91) |
| new mechanism (Sdk) (O36) | student assignments (Y40) |
| old Chicago mechanism (Chik) (E11) | manipulability (D91) |