slight evidence of increased impact with greater duration. In particular, there is a 10 percent increase in the prevalence of positive coefficients between exposure of 4-12 months to 13+ months and an increase from 0.60 to 0.70 standard deviations of the outcomes with the same increase in exposure. On the other hand, the summary in the last two columns of Table 10 indicates substantial concentration of significant positive program impacts among younger children: 64 percent (or 41 of 64) of these impacts are for children two- or three-years old at the time of Round 3. The average magnitude of the impacts is 0.90 standard deviations for two-year olds and 0.49 standard deviations for three-year old, but only in the 0.24-0.29 range for children older than three.

# **5. Conclusion**

We analyze the effects of an important ECD initiative in a developing country setting. The individual parts of the package of services delivered by the program in the Philippines are generally not new, but the program has changed the country’s approach to ECD by linking sectoral policies that affect young children and by integrating interventions that include center-based and home-based programs. We use rich and detailed longitudinal information on children, their families and communities, as well as data on the program itself, to estimate treatment effects. The difference-in-difference propensity score matching methods we use allow impacts to vary by both exposure to the program and the ages of children while controlling for observed characteristics and unobserved characteristics that are fixed and display common trends between program and non-program areas. Our results provide important insights on the effectiveness of ECD interventions in this low income setting.

The findings suggest that the ECD program is benefiting children in important respects. We find significant positive intent-to-treat impacts on the majority of the indicators of child development that we consider, particularly those related to child cognitive, social, motor skills and language development as well as short-term nutritional status. The incorporation of information about the variation of program exposure and child age is valuable because we can test to what extent the program impacts are sensitive to duration of exposure or are concentrated among particular age ranges of children. We find that the program impacts seem to increase with duration, particularly with duration beyond 12 months. We also find that positive program effects vary depending on the child’s age. In particular, cognitive, social, motor and language development among children below age four at the time of the final survey round improved significantly and substantially in program areas relative to non-program areas. Younger children exhibit faster rates of change in psycho-social development than do older children, and thus may be more receptive to interventions that aim to improve developmental outcomes. These impacts are not trivial: among two- and three-year-olds exposed to the program, Z-scores are one-half to 1.8 of a standard deviation higher for motor and language development. The prevalence and magnitudes of estimated positive program impacts are much less for older children.

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