Abdulkadiroglu, AtilaPathak, ParagRoth, Alvin2013-09-192009Abdulkadiroglu, Atila, Parag A. Pathak, and Alvin E. Roth. 2009. Strategy-proofness versus efficiency in matching with indifferences: Redesigning the NYC high school match. American Economic Review 99(5): 1954-1978.0002-8282http://nrs.harvard.edu/urn-3:HUL.InstRepos:11077572The design of the New York City (NYC) high school match involved trade-offs among efficiency, stability, and strategy-proofness that raise new theoretical questions. We analyze a model with indifferences -- ties -- in school preferences. Simulations with field data and the theory favor breaking indifferences the same way at every school -- single tiebreaking -- in a student-proposing deferred acceptance mechanism. Any inefficiency associated with a realized tiebreaking cannot be removed without harming student incentives. Finally, we empirically document the extent of potential efficiency loss associated with strategy-proofness and stability, and direct attention to some open questions. (JEL C78, D82, I21)en-USbargaining theorymatching theoryJournal Article2013-09-1910.1257/aer.99.5.1954