This is the percentage of each group of US men aged 25-40 who are married with children (they don’t have to be living at home) by year and race, from the Census’ Current Population Survey. MWDAD is married white dads, MHDAD is married Hispanic dads, and MBDAD is married black dads. Obviously there’s some kind of data issue in the late 90s (the marriage values for these years look weird in general), but the overall decline is quite remarkable.
I’m not 100% convinced that dads make a huge difference to their kid’s individual development; there are of course reasonable arguments on either side. But I’ve become convinced that the end of married fatherhood is a hugely politically and socially destabilizing force, and that the particular form of the married family was deeply important to both the rise of capitalism and the gradual expansion of liberty where and when it occurred. There are multiple reasons to doubt Deirdre McCloskey’s sanguine conclusion that The Great Enrichment of capitalist wealth and political equality will expand to every corner of the globe, but this seems like one of the important ones.