It is unclear if vouchers increase educational productivity or are purely redistributive, benefiting recipients by giving them access to more desirable peers at others’ expense. To examine this, we study an educational voucher programme in Colombia which allocated vouchers by lottery. Among voucher applicants to vocational schools, lottery winners were less likely to attend academic secondary schools and thus had peers with less desirable observable characteristics. Despite this, lottery winners had better educational outcomes. In this population, vouchers improved educational outcomes through channels beyond redistribution of desirable peers. We discuss potential channels which may explain the observed effects.