Table 5

Treatment effects on achievement z-score by low-income status using IHDP HLBW sample with ECLS-B weights

Outcome (sample size) Model
ABC
Age 8 reading (n=308)Treatment−0.116
(0.209)		−0.041
(0.261)		−0.456
(0.267)
 Low income−0.643***
(0.156)		−0.936***
(0.123)
 Treatment × (low income)0.804***
(0.184)
Age 8 Math (n=312)Treatment0.120
(0.149)		0.187
(0.206)		−0.137
(0.197)
 Low income−0.594*
(0.257)		−0.830**
(0.281)
 Treatment × (low income)0.636**
(0.224)

  • Coefficient significance (within site correlation corrected standard errors):

  • ↵* 0.10

  • ↵** 0.05

  • ↵*** 0.01. All models also condition on child gender, birth weight, gestational age at birth, neonatal health index, and site indicators. Estimates in appendix.