… is from pages 368-369 of the late Wesleyan University economic historian Stanley Lebergott’s indispensable 1984 book, The Americans: An Economic Record (footnotes deleted):
Major changes escalated in the twentieth century. Rising workers’ incomes enabled families to buy appliances that cut the work day more substantially, and freed housewives to enter the labor force….
[F]ewer families took in boarders and lodgers. In 1900 one urban family out of four shared its home with a boarder or lodger; by 1930, only 11 percent did so, and by 1970, a mere 2 percent did.
Together, such factors reduced housewives’ meal preparation and cleaning time from 6 hours a day to 1 1/2. Time was thus freed for education, the pursuit of “culture,” leisure.
DBx: Don’t forget this splendid TED talk by the late Hans Rosling: