Table 2.

Parents' ages at first birth and offspring count. (Dependent variable is number of offspring. Results are estimated by OLS, with robust standard errors in parentheses.)

woman's age at first birth	−0.0845*** (0.00198)
square of woman's age at first birth	0.000140** (6.01e − 05)
man's age at first birth	0.0185*** (0.00183)
square of man's age at first birth	−0.000924*** (4.62e − 05)
woman's age at first birth × man's age at first birth	0.000712*** (9.03e − 05)
constant	4.022*** (0.0262)
observations	861 898
R2	0.140

*p < 0.1.

**p < 0.05.

***p < 0.01.