This article estimates the determinants of cognitive skills in Jamaican primary education. We take an eclectic approach, integrating the production function framework favored by economists with the concerns of educators about pedagogical processes and those of sociologists regarding school organization and management. At the same time, we correct for selectivity biases induced by school choice. We use an unusually rich data set, the 1990 Jamaican Survey of Living Conditions, which includes not only scores on cognitive achievement tests but also detailed information on each child's household and the primary school he or she attends. We find that all three components—physical and pedagogical inputs, pedagogical practices, and school organization and climate— influence student achievement. Our policy simulations suggest that a focus on inputs alone may be misplaced in school systems with input levels as high as those found in Jamaica; school reforms that concentrate on just a few pedagogical practices could lead to substantial improvements in student achievement.