. 2007 Dec 4;4(1):78–79. doi: 10.1098/rsbl.2007.0514

Table 1.

Parental age difference and offspring count. (Dependent variable is the number of children born. Results are estimated with OLS. Heteroskedasticity-robust standard errors within parenthesis. Two asterisks denote statistical significance at the 1% level and one asterisk at the 10% level in a t-test.)

	number of children born

	(1)	(2)	(3)	(4)
constant	6.053^**	6.343^**	14.689^**	14.560^**
constant	(0.046)	(0.055)	(0.228)	(0.239)
age difference	0.0820^**	0.1371^**	−0.0222^**	−0.0139^*
age difference	(0.0072)	(0.0071)	(0.0064)	(0.0069)
age difference sq.		−0.00855^**		−0.00099^*
age difference sq.		(0.00078)		(0.00052)
woman's age at marriage			−0.3183^**	−0.3123^**
woman's age at marriage			(0.0078)	(0.0085)
N	4285	4285	4285	4285
R²	0.029	0.074	0.278	0.278