Table 2.

Main results: Coefficients from linear probability models controlling for education, cohort dummy variables, and a quadratic polynomial in age at first birth

	(1) Died Between 1991 and 2010	(2) Lung Cancer/COPD	(3) Heart Attack/Stroke	(4) Femur Fracture
A. Twins	0.037**	0.013**	0.018**	0.005
	(0.009)	(0.004)	(0.007)	(0.004)
B. Same-Sex Twins	0.038**	0.013*	0.020*	0.005
	(0.011)	(0.005)	(0.008)	(0.005)
Unconditional Mean	0.287	0.044	0.136	0.047
Number of Observations	404,286	404,286	404,286	404,286

Notes: Each coefficient–standard error pair comes from a separate regression. In panel A, the reference group is mothers with a singleton first birth. In panel B, the reference group is mothers with singletons or opposite-sex twins at first birth. Robust standard errors are shown in parentheses.

*p < .05; **p < .01