Sensitivity of Estimated Effects of Pre-K on Test Scores to Estimation Sample
| Pre-K | Test Scores | ||||
|---|---|---|---|---|---|
| First-Stage (1) | RF (ITT) (2) | IV (TOT) (3) | OLS (4) | ||
| Panel A: Baseline | |||||
| Universal (N = 3,400) | 0.211 (0.047) | 0.120 (0.065) | 0.569 (0.315) | −0.069 (0.048) | |
| Targeted (N = 3,950) | 0.118 (0.034) | −0.044 (0.060) | −0.373 (0.513) | −0.093 (0.042) | |
| p-value on difference | 0.057 | 0.012 | 0.046 | 0.609 | |
| Panel B: Sample ±4 Months from Thresholda | |||||
| Universal (N = 2,000) | 0.226 (0.054) | 0.203 (0.075) | 0.900 (0.350) | −0.050 (0.071) | |
| Targeted (N = 2,350) | 0.129 (0.039) | 0.042 (0.068) | 0.321 (0.527) | −0.067 (0.056) | |
| p-value on difference | 0.091 | 0.024 | 0.197 | 0.808 | |
| Panel C: Identification ± 4 Months from Thresholdb | |||||
| Universal (N = 3,400) | 0.218 (0.055) | 0.220 (0.074) | 1.007 (0.377) | −0.066 (0.047) | |
| Targeted (N = 3,950) | 0.143 (0.039) | 0.040 (0.070) | 0.278 (0.488) | −0.092 (0.042) | |
| p-value on difference | 0.191 | 0.015 | 0.104 | 0.587 | |
| Panel D: Expanded Sample (+ Middle-of-Month Cutoffs)c | |||||
| Universal (N = 3,450) | 0.212 (0.045) | 0.127 (0.065) | 0.600 (0.314) | −0.046 (0.048) | |
| Targeted (N = 4,250) | 0.118 (0.032) | −0.020 (0.059) | −0.170 (0.503) | −0.089 (0.040) | |
| p-value on difference | 0.042 | 0.022 | 0.089 | 0.379 | |
| Panel E: Restricted Sample (Aug. 31/Sept. 1 Cutoffs)d | |||||
| Universal (N = 1,800) | 0.267 (0.054) | 0.150 (0.085) | 0.561 (0.311) | −0.086 (0.072) | |
| Targeted (N = 1,850) | 0.192 (0.037) | −0.038 (0.076) | −0.201 (0.397) | −0.095 (0.061) | |
| p-value on difference | 0.173 | 0.010 | 0.023 | 0.908 | |
Source: U.S. Department of Education, National Center for Education Statistics, Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) of children born in calendar year 2001, “Children’s Birth Certificates” (collection at nine months), “Parent-Guardian Interviews,” “Direct Child Assessments,” and “Early Care and Education Providers” (collection at 48 months).
Notes: See note to Table 4.
↵aSample further limited to respondents with birthdays within four months of the cutoff birth date for kindergarten entry in their Wave 3 state of residence.
↵bInteractions between treat and indicators for birth four to five months and six to seven months after cutoff included.
↵cSample expanded to include respondents residing in treatment states with middle-of-month cutoffs (targeted: AR, NC; universal: ME) not born in the cutoff birth date month.
↵dSample limited to treatment and comparison states with Aug. 31 or Sept. 1 cutoffs (Online Appendix Tables 1 and 2).