Changing the Boston School Choice Mechanism: Strategy-proofness as Equal Access,”NBER Working Paper 11965

In July 2005 the Boston School Committee voted to replace the existing Boston school choice mechanism with a deferred acceptance mechanism that simplifies the strategic choices facing parents. This paper presents the empirical case against the previous Boston mechanism, a priority matching mechanism, and the case in favor of the change to a strategy-proof mechanism. We present evidence both of sophisticated strategic behav-ior among some parents, and of unsophisticated strategic behavior by others. We find evidence that some parents pay close attention to the capacity constraints of different schools, while others appear not to. In particular, we identify a certain kind of mistake that can be observed in the data without knowing the true preferences of a family. Fam-ilies that make this mistake are disproportionately unassigned, and in many cases they would have been assigned but for the mistake. This interaction between sophisticated and unsophisticated players identifies a new rationale for strategy-proof mechanisms based on fairness, and was a critical argument in Boston’s decision to change the mechanism. ∗We are grateful to Carleton Jones, Valerie Edwards, and other staff members at Boston Public School