a few cases and when taken as a set, they are jointly significantly different from zero. For example, not having a father in the household has a significantly larger positive association with attrition in program areas. Living in a barangay with a paved road is significantly more likely to be positively related to migrating out of a non-program barangay, perhaps reflecting the fact that out-migration is facilitated by the easy crossing to Manila. However, we note that interpretation of these interaction terms is complicated since they may reflect unobserved behavioral mechanisms. Since a number of family background variables have differential effects on attrition by treatment status, there is a need to correct for possible sources of bias. To correct for attrition on observables, we re-weighted the observations for attrition using predicted values from the regression shown in Table B.2 as in Behrman, Parker and Todd (2006), which provides a formal discussion of this procedure.

# **Measures of early child development**

Table 5 presents means for different ECD indicators in Rounds 1 and 3 by whether the child resides in an area that received the ECD program.

_Cognitive, social, motor and language development._ The project collected information on seven domains of child development using an instrument developed for the evaluation by a team of Philippine experts.<sup>10</sup> The seven domains are: 1) _Gross motor skills_ —movements of the entire body, trunk and/or limbs (e.g., sitting, walking, climbing and jumping); 2) _Fine motor skills_ —movements of the hands and fingers (e.g., reaching, grasping, and writing); 3) _Receptive language_ —understanding of verbal communication; 4) _Expressive language_ —use of language to convey thoughts and needs; 5) _Cognitive development_ —ability to think, reason, understand concepts and solve problems, as well as early literacy and numeracy skills; 6) _Social-emotional development_ —ability to respond in an age- and culturally appropriate manner to social situations and interpersonal relationships; and 7) _Self help_ —ability to perform daily living activities such as feeding, dressing and toileting. Each domain contains between nine and 22 items that are developmentally sequenced to increase in the degree of difficulty of tasks. Within a domain, each item takes a value of one for presence of a skill and zero if not present. The sums of the raw scores are scaled within a series of age intervals to reflect a distribution with a mean of 10 and a standard deviation of three.<sup>11</sup> ________________ 10 The Revised ECD Checklist (REC) was developed by a team of experts led by Drs. Lourdes Ledesma and Elizabeth Ventura of the Department of Psychology at the University of the Philippines, Diliman.

11 The scores are normed, controlling for age and sex, by comparing them with the scores for a sample of 10,915 Filipino children age zero to six years old drawn from regions 6, 7, 8 along with Regions 3 and 12 (Central Luzon and Central Mindanao). The instrument was applied to all children except those with serious health problems (e.g., poorly controlled seizures), debilitating anomalies (e.g., meningocoeles and cerebral palsy) or those with special needs (e.g., autism).

10