Table 4.

a Estimated Impacts on Percentage Helped with 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	52	61	5.2 (5.7)	−7.3 (8.1)	6.3 (4.5)	−3.3 (4.9)	97	97	754	676
8–11	.3	52	49	−10.0 (3.2)	−12.3 (3.4)	−7.5 (2.9)	−10.4 (3.1)	97	97	1880	1692
12–14	.3	30	33	2.1 (4.2)	2.0 (4.0)	2.0 (3.6)	2.7 (3.7)	97	97	950	870
15–18	.3	17	13	−4.7 (5.6)	−3.1 (5.9)	−4.9 (4.4)	−2.0 (4.5)	94	94	342	304
6–18	.3	43	46	−3.8 (2.3)	−6.8 (2.5)	−2.5 (2.0)	−4.9 (1.9)	97	97	3926	3542

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	57	58	−4.7 (4.7)	−5.2 (5.3)	−3.6 (4.3)	−5.9 (5.0)	97	97	818	739
8–11	.3	50	52	−5.3 (3.0)	−6.5 (3.3)	−4.1 (2.8)	−6.0 (2.8)	98	97	1931	1743
12–14	.3	26	29	2.3 (4.5)	−6.4 (4.7)	2.3 (3.7)	−5.2 (3.9)	97	97	876	783
15–18	.3	10	14	0.4 (4.5)	−2.9 (5.5)	3.0 (3.6)	−0.2 (4.0)	96	96	362	308
6–18	.3	42	45	−2.9 (2.0)	−5.9 (2.2)	−1.9 (1.8)	−5.3 (1.9)	97	97	3987	3573

^†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