School choice: Impossibilities for affirmative action

This paper investigates the welfare effects of affirmative action policies in school choice. We show that affirmative action policies can have perverse consequences. Specifically, we demonstrate that there are market situations in which affirmative action policies inevitably hurt every minority student – the purported beneficiaries – under any stable matching mechanism. Furthermore, we show that another famous mechanism, the top trading cycles mechanism, suffers from the same drawback.