American parental leave policies are a bit of an outlier when compared with other OECD: https://qz.com/1275938/22-american-mothers-on-what-its-like-to-go-back-

American parental leave policies are a bit of an outlier when compared with other OECD: https://qz.com/1275938/22-american-mothers-on-what-its-like-to-go-back-to-work-after-maternity-leave https://qz.com/1275938/22-american-mothers-on-what-its-like-... If rich mothers give up work after giving birth and poor mothers return quickly to work, that could have an impact. And in America, rich/poor and white/black trends are big confounders.