Recent Trends in Labor Supply Decisions among Married Couples in the United States
Abstract
It is well known that married women's labor supply in the United States began to increase significantly in the late 1950s, peaking in the late 1990s followed by a very slow increase since then, while married men's labor supply has steadily declined over time. However, this aggregate trend for women’s labor supply masks heterogeneity in labor supply behavior—working hours among women with children (those with at least one child under the age of 14) have continued to rise in recent decades. In this paper, we focus on the period since the late 1990s, aiming to explain labor supply behavior among mothers.Using CPS March Supplement data (1998–2023), we document that married women, especially those with children, experienced the largest increases in work hours compared to their counterparts without children. In contrast, married men with children saw the greatest declines in work hours relative to men without children. Additionally, American Time Use Survey data show that fathers have increased the time they spend on childcare. Meanwhile, fertility rates have slightly risen, with childbirth occurring later than in the late 1990s.
Using a two-earner life-cycle model, we find that a reduced gender wage gap and increased male wage uncertainty significantly affect joint labor supply and fertility. The narrowing wage gap has a stronger impact on households with children, increasing mothers’ work hours while reducing fathers’—paired with an increase in fathers’ childcare time, highlighting the role of substitutability between mothers’ and fathers’ childcare time. The relative rise in women's wages, combined with men’s increased role in childcare, interactively drives women to work more, accelerating their human capital accumulation. In contrast, the effect of increased wage uncertainty among men is more neutral, as it leads to a similar increase in work hours for all women, regardless of the presence of children.