The Boston mechanism is a school allocation procedure that is widely used around the world. To resolve overdemands, priority is often given to families who live in the neighborhood school. We note that such priorities define some schools as being safer. We exploit an unexpected change in the definition of neighborhood in Barcelona to show that when allowing school choice under the BM with priorities: (1) the resulting allocation is not very different from a neighborhood-based assignment, and (2) important inequalities emerge beyond parents’ naivete found in the literature.