What are the most efficient means to ensure basic learning competencies for a high number of children? This question is analyzed on the basis of the exceptionally rich data set provided by the “Program on the Analysis of Education Systems” (PASEC), standardized and comparable for the five countries Burkina Faso, Cameroon, Côte d'Ivoire, Madagascar and Senegal. A Hierarchical Linear Model (HLM) is used to assess the individual, school level, and national characteristics determining fifth-grade students' achievement in French and mathematics. Special consideration is given to institutional factors. A further question addressed is the possibility of a tradeoff between enrollment and education quality.