using the same covariates as for the whole sample. In the major-ity of pre-treatment variables the difference between covariateswas non-significant (p > 0.01). These analyses provide informationon which children benefit the most from ECCE programs and howeffective these programs are in reducing cognitive gaps, especiallyfor children from low and middle-low income groups. Childrenfrom the middle-low SES group, followed by those from the middleSES group, seem to benefit the most from ECCE programs, accord-ing to difference in means analyses done for the matched sampleas well as the adjusted-regression analyses.Table 5 shows how there is no ECCE effect for children fromthe upper-middle SES group (p > 0.05), and the same being true inreading and social sciences for children from the low SES group.However, low SES children who attended ECCE did perform betteron the math test (by 4.8 points; 0.08 SD) than those who did notattend