Child Gender and Married Women's Overwork: Evidence from Rural-Urban Migrants in China.

Overwork is one of the risk factors for the work-related burden of disease. In China, nearly a quarter of migrant women are overworked. Working long hours can significantly increase the possibility of migrant women suffering from hypertension and hyperglycemia. The phenomenon of overtime work of migrant women and their health conditions deserves attention. Based on the China Migrants Dynamic Survey in 2016, this study indicates that giving birth to a boy may exacerbate overtime work among migrant women and having more boys in a family increases the probability of women's overwork. Empirical results confirmed the existence of son preferences in China. Compared with women who gave birth to boys, women who gave birth to girls have a lower probability of being a workaholic due to a future fertility plan. Furthermore, the overwork of women is also due to the great economic burden on families to buy a wedding house, brought on by the birth of boys. To overcome the endogenous problem caused by this omitted explanatory variable, this study uses each province's relative sex ratio at birth in 2010 as the instrumental variable of the firstborn's gender. The IV results illustrate that the birth of boys still significantly exacerbates women's overwork. Furthermore, considering age heterogeneity, the influence of son preference on women's overtime work exists throughout their labor life cycle. This paper provides a new perspective for understanding migrant women's overtime work and their health issues in urban China.