Why do we work less?

I am sympathetic to the argument by Robert Frank and others that competition for positional goods is a major factor driving our behaviour. The natural outcome of this is that we should want to work more, or at least more than anyone else. However, recent trends in working hours do not neatly fit with this story.

When Jared Diamond proposed that agriculture was the worst mistake in the history of the human race, he was referring primarily to work hours. Diamond writes:

[T]he average time devoted each week to obtaining food is only 12 to 19 hours for one group of Bushmen, 14 hours or less for the Hadza nomads of Tanzania. One Bushman, when asked why he hadn’t emulated neighboring tribes by adopting agriculture, replied, “Why should we, when there are so many mongongo nuts in the world?”

There are plenty of studies which support this view. Hans-Joachim Voth summarises the results of a series of studies in his book Time and Work in England 1750-1830 and notes that worUking hours increased from an average 4.9 hours per day in hunter-gatherer communities to 7.4 hours per day in mixed societies through to 10.9 hours per day in advanced sedentary agricultural societies.

Voth also describes how work hours increased further around the time of the Industrial Revolution, with the average hours worked per year by a London resident increasing from 2,288 hours per year in the 1750s to 3,366 hours per year in 1800-1803 and in 1830. This equates to around 64 hours per week.

But work hours peaked around that time. Today, workers in the United States work, on average, around 35 hours per week. With the exception of South Korea, almost no developed country has an average work week of more than 40 hours. Work hours have generally been declining for over 150 years.

Why, with competition for positional goods such as entry to good schools and neighbourhoods, are we working less? The story about competition for positional goods needs to accommodate the fact that while we still work more than hunter-gatherers, recent trends are towards working less.