Throughout the first half of the 20th century, the working week gradually got shorter and shorter. As technological advances powered economic growth, workers reaped the gains not just in the form of higher pay, but more leisure time. The economist John Maynard Keynes predicted we'd eventually all be working a 15-hour week. Even in the 1970s the expectation that 8 hour days would be reduced to 6 was widely held across the political spectrum. But this all ground to a halt in the 1980s.