. Author manuscript; available in PMC: 2012 Jul 1.

Published in final edited form as: J Hum Cap. 2011 Summer;5(2):207–254. doi: 10.1086/660885

Table 6.

Effects of Smoking Participation and Number of Cigarettes during Pregnancy on the Probability of High Neurodevelopment Risk Status^a Excluding Maternal Characteristics

Model	Total Sample	Low Socioeconomic Status	High Socioeconomics status
	Smoking participation
Probit	0.091^*** (0.030)	0.079^** (0.040)	0.099 (0.063)
Bivariate Probit	0.503^** (0.207)	0.546^*** (0.161)	0.253 (0.635)
F-statistic	22.88^*** [2, 23]	11.86^*** [2, 22]	7.24^*** [2, 23]
Over-identification Chi-square [1]	2.08	1.8	1.98
Exogeneity Chi-square [1]	2.73^*	3.93^**	0.07

	Cigarettes
Probit	0.007^** (0.003)	0.007^* (0.004)	0.007 (0.006)
IV Probit	0.042^* (0.022)	0.029 (0.021)	-
F-statistic [df]	48.35^*** [2,23]	20.36^*** [2, 22]	-
Over-identification Chi-square [1]	0.81	0.63	-
Exogeneity Chi-square [1]	4.14^**	1.38

Note: The model is a nested specification of equation (5) that excludes maternal health, socioeconomic status and demographic characteristics, and includes only smoking (or cigarette number), child’s ancestry, number of older siblings, and country fixed effects. Standard errors are in parentheses.

^{*, ** and ***}

indicate p <0.1, <0.05 and <0.01, respectively.