DECLINES in hours worked per person are among the least-sung benefits of economic development. In the late 19th century workers in industrialised economies knew labour and little else. In 1870 full-time work generally meant between 60 and 70 hours of labour per week, or more than 3,000 hours per year. Over the century that followed rising incomes were accompanied by a steady drop in weekly hours, which had fallen to about 40, on average, by 1970. Though less conspicuous a boon than larger pay packets or higher living standards, the drop was a gift to working people of a thousand or so precious hours of free time each year.

Hours worked are hard to measure. But the best analyses suggest that such gifts have been far less generous in the years since, in some countries at least (see chart). In France and Germany hours worked per person have continued to drop over the past few decades, albeit more slowly than in the past. In Germany, where one of the largest trade unions recently won for its workers the right to a 28-hour working week, employees now put in fewer than 1,400 hours per year. The decline in America and Britain has been substantially smaller; indeed hours worked in those countries have actually risen since the 2000s.

Why should time spent in work vary so much? Analyses of differences between countries focus on culture: of course leisure-loving Europeans put in fewer hours than puritanical Americans and striving Koreans. Such stories are often unsatisfying, however. Italians and Greeks work many more hours than their supposedly more diligent northern neighbours, for instance. Economists, for their part, often think about the choice to work more or fewer hours in terms of competing “substitution” and “income” effects. Forces that increase the return to work (such as reductions in marginal tax rates or higher pay) make each hour of work more lucrative, and can therefore cause workers to choose to work more: to substitute working hours for leisure time. On the other hand, when people are richer they tend to consume more of the things they enjoy, including leisure. So, a higher effective return to work, by raising income, can also lead to a decline.

Read more about working hours in Free exchange