Decisions about childbearing and market work are significantly interrelated. Although there are many estimates of the effects of fertility on labor supply, few of them have adequately addressed the problems of simultaneity inherent in these choices. In our research we use exogenous variations in...

We use exogenous variations in fertility due to twin births to measure the impact of an unplanned child on married women's labor supply and earnings. Although the overall effects of an unplanned birth on labor supply are small, we find significant effects in the years immediately following the...