The gap between male and female earnings. The weight of research suggests that, after accounting for the constraints women face from bearing and rearing children, there is little left to explain. Claudia Goldin of Harvard University, who won a Nobel prize in 2023, seemed to settle the debate: motherhood, her work suggested, explains basically all of the wage gap.
A handful of papers published in the mid-2020s, based on Scandinavian health records matched with income data, reignited the debate. Researchers examined women undergoing in vitro fertilisation (IVF)—who clearly wanted children—and compared the long-term wages of those who fell pregnant with those who did not. At first the mothers earned much less, but the gap shrank over time; around 10-15 years later, the mothers even earned a small premium.
A study by Camille Landais of the London School of Economics and others exploited a different natural experiment: women with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, a rare condition in which a girl is born without a uterus but otherwise develops normally. These women know early in life that they will not bear children, and so may make different investments in their human capital—spending more on education, for instance, knowing they will not step back from their careers. The study found that women with MRKH earn much the same as other women and men in early adulthood. Then, in their 30s and 40s, as the wage gap between men and women opens up, the women with MRKH follow a different path: their wage trajectory is almost identical to that of their male peers. Remove both motherhood and any decisions women might make while anticipating it, and the wage gap seems to vanish.
QOTD: "Sure, I turned down a drink once. Didn't understand the question."