Krugman is correct that women spend more time in paid jobs than before. But women also spend much less time doing unpaid household work. Overall, men and women enjoy three to six hours a week more free time than in the 1960s — Americans have more leisure today than a generation ago.
In fact, lower income Americans have more free time today than upper income Americans do. It seems that people face a trade-off between higher incomes with less free time or lower incomes with more free time.
Speaking personally, I know I could probably earn more if I put in more time at work. But I'm happy to forgo that extra income in favor of spending more time at home, with my family.