Sentences to ponder

We find that interventions (e.g., busing) that move children to a more favorable neighborhood have large effects but lose impact when they are scaled up because parents’ equilibrium responses push against successful integration with the new peer group.

That is from Francesco Agostinelli, Matthias Doepke, Giuseppe Sorrenti & Fabrizio Zilibotti.  Here is the NBER version, here is the JPE version.