Table 3.

Contribution of Gender Differences in Levels and Effects of Early Externalizing Problems to the Gender Gap in Years of Schooling Completed for NLSY-C Children Born 1983 to 1986, Based on a Two-Way Decomposition Model Including Early Externalizing Problems, Early Childhood Factors, and Demographic Controls (Reference Group: Boys)^a

	Means		Diff. in Means	OLS Regression Coefficients				Contribution of Diff. in Levels	Contribution of Diff. in Coefficients	Total Contribution of Levels & Coefficients	Prop. of Positive Effects on Gap	Prop. of Negative Effects on Gap
	(1)	(2)	(3)	(4)		(5)		(6)	(7)	(8)	(9)	(10)
	F	M	F-M	F	Sig	M	Sig
Externalizing Problems, Ages 4–5	1.971	2.603	−0.632	−0.038		−0.169	***	0.107	0.341	0.448	0.163	0.000
Observations (N)	881	780		881		780
Overall Contribution of Early Externalizing Problems, Early Childhood Factors, and Controls to the Gender Gap in Years of Schooling Units:								0.152	0.601	0.754	1.000	1.000
Overall Contribution to the Gender Gap as a Proportion of Gap Driven by Levels vs. Effects:								0.202	0.798	1.000

^***p<0.001,

^**p<0.01,

^*p<0.05,

⁺p<0.10 (two-tailed t-tests for a statistically significant difference from 0). In addition to early externalizing problems, both decompositions include all the early childhood and demographic control variables shown in Table 2. Complete decomposition results are shown in the Appendix.

^aThese models use boys’ coefficients as the reference when calculating each variable’s contribution to the gap in schooling due to gender differences in mean levels and boys’ means as the reference when calculating each variable’s contribution due to gender differences in coefficients (i.e., effects).

Source: The 1983 to 1986 birth cohorts of the Children of the National Longitudinal Survey of Youth:1979 (NLSY-C; https://www.nlsinfo.org/content/cohorts/nlsy79-children) and matched National Longitudinal Survey of Youth:1979 (mother sample). The low-income white and military oversamples are excluded.

Note: The National Longitudinal Survey of Youth-Child Supplement (NLSY-C) consists of a nationally representative sample of children born to women ages 14 to 21 in 1979; after excluding the poor white and military oversamples, the working sample in this study is restricted to the 1,857 children born 1983 to 1986, whose mothers were therefore 18 to 29 years at birth. Children born 1983 to 1986 were born early enough to be age 26 to 29 as of the 2012 follow-up survey, but late enough to have early behavior problems information measured at ages 4 to 5 beginning in 1986, at which point these items were introduced for children ages 4 to 16. I used multiple imputation of 20 datasets to handle item-missingness. Model estimates use inverse-probability weighting to deal with stratified sample design (minority oversampling) and sample attrition by the 2012 follow-up wave (weights are described at: https://www.nlsinfo.org/weights/nlsy79). Once inverse-probability survey weights areapplied, the working sample with complete attainment and behavior information drops from 1,857 to 1,661 children (881 girls, 780 boys).