In 1930, economist John Maynard Keynes predicted that by 2030 the American economy would be so productive as to allow for a 15-hour work week, according to a recent story in The Atlantic.

As The Atlantic reminds us, three quarters of the way there, we’re not even close.

For a while it appeared that Keynes’s prediction would come true. The average workweek had decreased from 47 hours a week in 1930 to less than 39 in 1970. But that’s when the decrease stopped:

“… [S]omething changed. Instead of continuing to decline, the duration of the workweek stayed put; it’s hovered just below 40 hours for nearly five decades.”

So what happened?

According to Harvard economist Benjamin Friedman, Keynes was right about increased productivity, but failed to take into account rising inequality:

“American inequality means that the gains of increasing productivity are not widely shared. In other words, most Americans are too poor to work less… Keynes’s prediction rests on the idea that ‘standard of life’ would continue rising for everyone. But Friedman says that’s not what has happened…”

Keynes’s prediction appeared in an essay (“Economic Possibilities for Our Grandchildren”) where he worried what Americans would do with their leisure time in a society that required so little work. A legitimate worry, but apparently one we can put off for yet a while longer.