A modification aimed at reducing the manipulability and inefficiency of the Boston school choice mechanism

The Boston mechanism (BOS) is widely used for the assignment of students to schools. Yet, BOS is highly manipulable and, therefore, may lead to Pareto inferior assignments. We propose a new indirect matching mechanism ( $${{ NBOS }}$$ NBOS ) that is a slight variant of BOS. $${{ NBOS }}$$ NBOS is less manipulable than BOS in two important ways: (i) students always have a best reply featuring truthful reported preference, (ii) rational students avoid particular re-rankings that are typical in BOS. Most importantly, the lower manipulability of $${{ NBOS }}$$ NBOS helps reaching more efficient assignments than those reached by BOS. We show that each equilibrium of BOS is associated to a set of equilibria of $${{ NBOS }}$$ NBOS , all of which are Pareto superior. $${{ NBOS }}$$ NBOS generalizes to a class of mechanisms whose members are even less manipulable than $${{ NBOS }}$$ NBOS .