There is substantial controversy regarding private school effects on academic achievement. A number of studies claim to show that Catholic and other private schools have a positive effect on academic achievement, especially with minorities. Critics claim that seemingly positive private school effects could be the result of selection rather than causation. Some proponents argue that Catholic schools might play a larger role in promoting an egalitarian society if grants or vouchers that could be used in the parochial school sector were made available to poor students. Critics point to studies showing mixed results of Catholic schools on academic achievement and downplay the effect of private competition on public education. This book examines the controversies concerning the measured effects of Catholic schooling on educational attainment, academic achievement, and other tangible outcomes. It focuses on the effects of Catholic schooling on test scores, homework, labour market outcomes, religiosity, public school achievement, and other outcomes such as alcohol and substance abuse. The volume also considers how Catholic schooling effects vary by location, minority status, and time period.