I agree; I share your intuition that the reverse was the case in the past (the poor working longer hours than the rich), so the numbers being what they are today bears out the conclusion that the change has been towards the rich working more than the poor. Unfortunately, I just haven’t been able to find a ton of data explicitly focusing on this exact question (as opposed to a ton of related ones grouped together by Our World In Data). Best I could come up with was this Economist article from 2014 (beware paywall):
the rich have begun to work longer hours than the poor. In 1965 men with a college degree, who tend to be richer, had a bit more leisure time than men who had only completed high school. But by 2005 the college-educated had eight hours less of it a week than the high-school grads. Figures from the American Time Use Survey, released last year, show that Americans with a bachelor’s degree or above work two hours more each day than those without a high-school diploma. Other research shows that the share of college-educated American men regularly working more than 50 hours a week rose from 24% in 1979 to 28% in 2006, but fell for high-school dropouts. The rich, it seems, are no longer the class of leisure.
I agree; I share your intuition that the reverse was the case in the past (the poor working longer hours than the rich), so the numbers being what they are today bears out the conclusion that the change has been towards the rich working more than the poor. Unfortunately, I just haven’t been able to find a ton of data explicitly focusing on this exact question (as opposed to a ton of related ones grouped together by Our World In Data). Best I could come up with was this Economist article from 2014 (beware paywall):