Table A5.

Two-level Regression Models of Early Developmental Milestones on Individual and County-level Variables.

	Late Walking	Late Talking	Late Counting	Late Toilet-Training
Individual-Level Coefficients
Maternal education	−0.080 ***	−0.165 ***	−0.549 ***	−0.283 ***
	(0.018)	(0.036)	(0.065)	(0.057)
Female	−0.104	−0.873 ***	−1.096 ***	−0.793 ***
	(0.078)	(0.142)	(0.248)	(0.213)
Birth cohort (ref: 1995–1999)
2000–2004	−0.393 ***	−0.621 **	−0.424	−0.279
	(0.119)	(0.210)	(0.364)	(0.318)
2005–2009	−1.023 ***	−1.479 ***	−4.589 ***	−5.271 ***
	(0.118)	(0.210)	(0.370)	(0.318)
After 2010	−1.188 ***	−1.478 ***	−5.100 ***	−5.969 ***
	(0.118)	(0.216)	(0.377)	(0.324)
Minority	0.360 *	−0.161	−0.609	0.046
	(0.167)	(0.315)	(0.559)	(0.472)
Birth weight (ref: normal weight)
Low birth weight	0.765 ***	1.649 ***	2.074 ***	1.610 **
	(0.185)	(0.333)	(0.591)	(0.502)
Unknown	1.312 ***	1.265 ***	5.592 ***	2.509 ***
	(0.150)	(0.265)	(0.469)	(0.408)
Gestational age (ref: ≥37 weeks)
<37 weeks	0.714 ***	0.007	−0.384	−0.237
	(0.210)	(0.382)	(0.682)	(0.585)
Urban hukou before age 3	−0.311 *	−0.359	−2.676 ***	−0.608+
	(0.127)	(0.237)	(0.414)	(0.353)
Maternal age at delivery (ref: <20)
20–24	0.056	−0.270	0.594	−0.014
	(0.221)	(0.398)	(0.702)	(0.603)
25–29	0.135	−0.070	1.087	0.219
	(0.222)	(0.401)	(0.707)	(0.607)
30–34	0.245	0.054	1.488 *	0.445
	(0.234)	(0.423)	(0.746)	(0.640)
35+	0.357	0.176	1.566 †	−0.608
	(0.262)	(0.476)	(0.842)	(0.716)
County-level coefficients
Ln (GDP per capita)	−0.414 ***	−0.301 †	−1.456 ***	0.096
	(0.079)	(0.165)	(0.298)	(0.244)
Urban population %	−0.001	−0.004	−0.048 ***	−0.031 **
	(0.003)	(0.007)	(0.013)	(0.011)
Cross-level interaction coefficients
Maternal education × Urban population %	0.001	0.001	0.006 **	0.003+
	(0.001)	(0.001)	(0.002)	(0.002)
Constant	18.690 ***	24.656 ***	51.363 ***	34.588 ***
	(0.783)	(1.624)	(2.928)	(2.412)
N	11,361	10,324	10,061	10,751

Notes. Standard errors in parentheses; † p < 0.1, * p < 0.05, ** p < 0.01, *** p < 0.001.