QUEEN’S BUSINESS SCHOOL ECONOMICS SEMINAR SERIES

Friday 25^th October

3pm

“Weak Misrepresentations”

Jorgen Kratz

University of York

Abstract: Much of the literature on school choice focuses on "strategy-proof" admission mechanisms. These mechanisms assign students to schools in a way that students' best application strategy is to rank the schools in accordance with their true preferences. Students can try to strategically misrepresent their true preferences in a number of ways, but this would never help them get into a more desirable school under a strategy-proof mechanism. This paper focuses on a particular type of misrepresentation commonly observed in practice, called "weak misrepresentations", and on mechanisms with the property that any student misrepresenting their preferences in this way is assigned to the same univerity they would have been assigned to under truth-telling. We show that a mechanism is strategy-proof if and only if it has this property. This characterisation provides a new method for evaluating incentives of applicants under any admission mechanism. We use the result to provide simple new proofs of the strategy-proofness of the Deferred Acceptance and Top Trading Cycles mechanisms.

QBS Conference Hub, Seminar Room 01.012