By Gender
Variables	All			Boy			Girl
	Coeff.	S. E	P-value	Coeff.	S. E	P-value	Coeff.	S. E	P-value
SNAP	1.563	0.382	< 0.001	0.754	0.488	0.124	2.410	0.543	< 0.001
SNAP2	−4.513	1.221	< 0.001	−2.554	1.504	0.091	−6.578	1.591	< 0.001
SNAP policy index	0.006	0.005	0.266	0.017	0.007	0.010	−0.006	0.007	0.411
Number of Household Members	−0.005	0.001	< 0.001	−0.005	0.002	0.005	−0.005	0.002	0.002
Gender of Child
Boys	Ref	Ref	Ref	-	-	-	-	-	-
Girls	< 0.001	0.003	0.979	-	-	-	-	-	-
Race/Ethnicity
Non-Hispanic White	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Non-Hispanic Black	0.136	0.006	< 0.001	0.133	0.007	< 0.001	0.140	0.008	< 0.001
Non-Hispanic Black	0.109	0.008	< 0.001	0.106	0.009	< 0.001	0.113	0.012	< 0.001
Other	0.068	0.007	< 0.001	0.063	0.011	< 0.001	0.073	0.010	< 0.001
Maternal Education
< High School	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
High School/GED	−0.023	0.004	< 0.001	−0.010	0.007	0.150	−0.036	0.006	< 0.001
Non-college graduate	−0.064	0.005	< 0.001	−0.053	0.007	< 0.001	−0.075	0.007	< 0.001
College graduate	−0.268	0.010	< 0.001	−0.264	0.011	< 0.001	−0.271	0.014	< 0.001
Age Group
19–23m	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
24–29m	< 0.001	0.004	0.866	0.004	0.006	0.419	−0.003	0.006	0.565
30–35m	−0.005	0.004	0.183	−0.003	0.006	0.643	−0.008	0.006	0.174
Age of Mother
≥ 30 years	−0.061	0.005	< 0.001	−0.054	0.005	< 0.001	−0.068	0.007	< 0.001
< 30 years	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Marital Status of Mother
Married	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Non-married	0.102	0.005	< 0.001	0.107	0.007	< 0.001	0.097	0.007	< 0.001
Interview Language
English	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Spanish	0.072	0.008	< 0.001	0.078	0.008	< 0.001	0.065	0.013	< 0.001
Other language	0.028	0.015	0.068	0.021	0.020	0.298	0.034	0.018	0.060
Birth Year	−0.003	0.001	0.021	−0.004	0.002	0.090	−0.003	0.002	0.194
Unemployment Rate	0.002	0.001	0.123	0.003	0.002	0.236	0.002	0.001	0.267
TANF Enrollment Rate	−0.878	0.621	0.159	−1.404	0.933	0.134	−0.323	0.744	0.664
CHIP Enrollment Rate	−0.135	0.127	0.292	0.055	0.150	0.714	−0.331	0.192	0.086
_cons	0.731	0.061	< 0.001	0.664	0.069	< 0.001	0.800	0.065	< 0.001
R2	0.161			0.162			0.164
Identification test‡	UW						UW

^†Controlling state dummy (the results of State variables were not included in this table), sex, race/ethnicity, education, child’s age, maternal age, maternal marital status, number of people in the household, interview language, birth year, TANF enrollment rate (# of enrolled participants/# of state population), CHIP/Children’s Health Insurance Program enrollment rate (# of enrolled children/# of children 18 or under in the state), and state unemployment rate. IV Variables including SNAP enrollment rates (SNAP, # of SNAP participants in that year/# of state population in that year), square of SNAP enrollment rates (SNAP²), and SNAP policy index.

^‡U means the under-identification test P < 0.05. Stock–Yogo tabulations based on the Cragg–Donald statistic were used for the weak identification test; W means the F statistic of the weak identification test > 10% maximal IV relative bias or > 10% maximal IV size.