We meta-analyze for impact and cost-effectiveness 94 studies from 47 conditional cash transfer programs in low- and middle-income countries worldwide, focusing on educational outcomes that include enrollment, attendance, dropout, and school completion. To conceptually guide and interpret the empirical findings of our meta-analysis, we present a simple economic framework on household decision making that generates predictions, all else constant, for the association between certain program context and design characteristics and impact estimates. We also present a simple model for the analysis of program costs, using it to compute cost-effectiveness estimates for a subsample of programs. For all schooling outcomes, we find strong support for heterogeneity in impact, transfer-effectiveness, and cost-effectiveness estimates. Our meta-analytic results of impact and transfer-effectiveness estimates provide support to some--but not all--of the predictions from the household decision-making model.