Table 5.

a Estimated Impacts on Hours Spent Doing Homework, in school in 2001–2002 Subgroup: Boys, Age 6–18 Local Linear matching†
Age in 2002	BW	Avg Trt in 2002	Avg Con in 2002	1 Year DID Match	2 Year DID Match	1 Year DID	2 Year DID	% Obs in Support~	%Obs in Support~~	1 Year Obs T+C	2 Year Obs T+C
6–7	.3	4.36	4.69	0.87 (0.40)	0.42 (0.56)	0.60 (0.36)	0.03 (0.38)	97	97	754	676
8–11	.3	5.86	5.89	0.51 (0.23)	0.33 (0.29)	0.41 (0.21)	0.22 (0.25)	97	97	1880	1692
12–14	.3	6.26	6.40	1.29 (0.43)	1.08 (0.44)	0.96 (0.40)	0.69 (0.41)	97	97	950	870
15–18	.3	7.86	6.46	1.15 (1.05)	−0.07 (1.07)	0.46 (0.88)	−0.60 (0.82)	96	96	257	228
6–18	.3	5.86	5.80	0.83 (0.18)	0.52 (0.22)	0.59 (0.16)	0.25 (0.19)	97	97	3841	3466

b Estimated Impacts on Percentage Helped with Homework, in school in 2001–2002 Subgroup: Girls, Age 6–18 Local Linear matching†
Age in 2002	BW	Avg Trt in 2002	Avg Con in 2002	1 Year DID Match	2 Year DID Match	1 Year DID	2 Year DID	% Obs in Support~	%Obs in Support~~	1 Year Obs T+C	2 Year Obs T+C
6–7	.3	4.19	4.98	1.38 (0.40)	0.34 (0.41)	1.17 (0.35)	0.45 (0.34)	97	97	818	739
8–11	.3	5.83	5.80	0.39 (0.25)	0.32 (0.25)	0.15 (0.23)	0.04 (0.23)	98	97	1931	1743
12–14	.3	7.27	6.67	0.19 (0.78)	−0.69 (0.64)	0.03 (0.47)	−0.69 (0.50)	97	97	876	783
15–18	.3	8.53	7.56	1.38 (1.57)	0.39 (1.33)	0.12 (1.08)	0.04 (1.00)	97	97	258	217
6–18	.3	6.03	5.93	0.61 (0.27)	0.09 (0.23)	0.33 (0.20)	−0.04 (0.19)	97	97	3883	3482

^†Difference-in-Difference estimator, imposing common support (2% trimming)

Standard errors based on bootstrap with 500 replications

^~Percentage of observations in the support region for 1-year estimations

^~~Percentage of observations in the support region for 2-year estimations

^†Difference-in-Difference estimator, imposing common support (2% trimming)

Standard errors based on bootstrap with 500 replications

^~Percentage of observations in the support region for 1-year estimations

^~~Percentage of observations in the support region for 2-year estimations