In times of increasing female labor market participation and policy efforts to allow for easier combinations of work and family life, it is important to understand the consequences of actively raising children and simultaneously pursuing a career for mothers' health. A large literature exists on the relation of fertility and maternal education, working status, income, and health. A central problems of this literature is the endogeneity of the fertility decision. In the context of health, maternal health might directly be related to family size or unobservables such as parents' preferences which may drive both fertility decisions and risky health behaviors or health care decisions.
In this paper we are interested in a specific aspect of fertility namely getting twins at first birth on mothers' long-term health. In contrast to previous studies we are not using twinning as instrumental variable (IV) since it violates the exclusion restriction. Based on Swedish administrative data we document strongly increased old-age mortality rates among mothers that potentially experienced a double burden from working and rasing children simulateneously. We use twins at first birth as an unplanned shock to fertility and proxy labor force attachment by stratifying the sample by education and pension income. In line with the double burden hypothesis, the effect of having twins is largest among highly educated mothers and those with above-median pension income. Deaths due to lung cancer, COPD and heart attacks, which the medical literatureare strongly associates with stress during life (e.g. from work-family conflicts, care-giving, and multiple role requirements of women) are over-proportionally increased.
The project is joint work with Johan Vikström (IFAU). Results have been summarized in a discussion paper and are currently presented at conferences.