Is Investment in Preprimary Education Too Low? : Lessons from (Quasi) Experimental Evidence across Countries

Many studies have estimated high rates of return for preprimary education provided to children between the ages of 3 and 6, yet coverage is not universal in high-income countries and is very low in low- and middle-income countries. This study uses a novel dataset of impact estimates from 55 (quasi-) experimental studies conducted around the world and meta-regression methods to investigate whether this preprimary investment is suboptimal. Average effect sizes suggest strong demand for preprimary services when offered and significant improvements in children's cognitive (0.15 sd) and executive functions, social-emotional learning, and behavior (0.12 sd) during the preprimary period, with no significant differences between high and low and middle income countries. Estimates from a more limited set of longitudinal studies indicate persistence of advantages of 0.07 sd in each type of skills beyond the preprimary period, suggesting that investments in preprimary education can make primary instruction more effective. In studies that report separate effects for populations that vary in socio-economic status, disadvantaged children benefit significantly more on average from preprimary interventions. Lastly, benefit-to-cost ratios estimated for a subset of studies conducted in low- and middle-income countries range from 1.7 to 103.5. Taken together, these results imply high returns and room for improvements in efficiency from reallocating the marginal dollar in existing budgets toward preprimary education