. 2007 Aug 7;274(1624):2491–2496. doi: 10.1098/rspb.2007.0524

Table 1.

High-status mothers bear more sons—pattern reinforced by post-neonatal mortality, US linked birth–infant death data 1983–1991 and 1995–2001. (All explanatory variables are indicator variables and scaled by 1/1000 (reported means pertain to the full sample of live births and are unscaled). For age, 20–34 years is the excluded category. For education, some college or more is the excluded category. All regressions include a constant and indicator variables for gestation length, birth weight and year-of-birth dummies. In regressions (4)–(6), these indicator variables are interacted with the indicator variable for whether the infant died. t-statistics in square brackets are computed using robust standard errors. ^***, significance at (or below) the 1% level; ^**, significance at or below the 5% level (but above the 1% level); ^*, significance at or below the 10% level (but above the 5% level.).)

	mean^a	(1)	(2)	(3)	(4)	(5)	(6)

		dependent variable: infant is male

		sample

		alive age 0^b0.513	infant deaths^c0.573	alive age 1^d	alive age 1 and decedents

					infant^c	neonatal^e	post-neonatal^f

						0.568^g	0.582^h
married	0.786				1.022^***	−5.383^**	1.132^***	1.132^***	1.132^***	1.132^***
married	0.786				[5.25]	[2.57]	[5.79]	[5.79]	[5.79]	[5.79]
sub-15 years	1.50×10⁻³	4.929^***	32.132^**	4.244^**	4.244^**	4.244^**	4.244^**
sub-15 years	1.50×10⁻³	[2.64]	[2.29]	[2.25]	[2.25]	[2.25]	[2.25]
15–17 years	0.037	2.965^***	24.301^***	2.679^***	2.679^***	2.679^***	2.679^***
15–17 years	0.037	[7.14]	[6.12]	[6.42]	[6.42]	[6.42]	[6.42]
18–19 years	0.072	1.282^***	17.059^***	1.076^***	1.076^***	1.076^***	1.076^***
18–19 years	0.072	[4.37]	[5.61]	[3.65]	[3.65]	[3.65]	[3.65]
35 years+	0.1	−1.613^***	−22.368^***	−1.485^***	−1.485^***	−1.485^***	−1.485^***
35 years+	0.1	[6.60]	[7.18]	[6.06]	[6.06]	[6.06]	[6.06]
EdMis	0.104	−2.086^***	−7.001^**	−2.133^***	−2.133^***	−2.133^***	−2.133^***
EdMis	0.104	[7.71]	[2.31]	[7.85]	[7.85]	[7.85]	[7.85]
EdLow	0.18	−3.064^***	0.974	−3.195^***	−3.195^***	−3.195^***	−3.195^***
EdLow	0.18	[13.44]	[0.36]	[13.97]	[13.97]	[13.97]	[13.97]
EdHS	0.324	−1.074^***	−0.435	−1.106^***	−1.106^***	−1.106^***	−1.106^***
EdHS	0.324	[6.07]	[0.18]	[6.24]	[6.24]	[6.24]	[6.24]
dead×
married					−6.515^***	0.919	−15.503^***
married					[3.09]	[0.34]	[4.68]
sub-15 years					27.888^**	32.017^*	21.991
sub-15 years					[1.97]	[1.81]	[0.93]
15–17 years					21.622^***	24.984^***	16.658^***
15–17 years					[5.41]	[4.77]	[2.71]
18–19 years					15.983^***	14.558^***	16.531^***
18–19 years					[5.23]	[3.58]	[3.58]
35 years+					−20.883^***	−17.174^***	−27.536^***
35 years+					[6.68]	[4.58]	[4.88]
EdMis					−4.869	−5.045	−5.526
EdMis					[1.60]	[1.35]	[1.05]
EdLow					4.169	3.158	2.567
EdLow					[1.52]	[0.89]	[0.59]
EdHS					0.67	−2.816	5.412
EdHS					[0.28]	[0.96]	[1.35]
dead	6.48×10⁻³				55.638^***	39.337^***	68.157^***
dead	6.48×10⁻³				[11.76]	[6.45]	[8.91]
N		48 023 459	310 974	47 712 485	48 023 459	47 905 746	47 830 195

Column values pertain to the mean of the independent variable in the same row. Row values pertain to the fraction males in the respective sample, unless otherwise indicated.

All live births.

Infant deaths refer to deaths in the first year after birth.

Live births minus infant deaths.

Neonatal deaths refer to death that took place 0–28 days after birth.

Post-neonatal deaths refer to death that took place 29–365 days after birth.

Pertains to the fraction males among neonatal decedents.

Pertains to the fraction males among post-neonatal decedents.