Useful evidence that we're all getting richer

We are often told that we should be working fewer hours. You know the sort of thing, Keynes said we'd all be working 15 hours a week by now so why aren't we? What is less often noted is that we are in fact all working fewer hours. The great reduction, of course, has come in unpaid working hours in the household. But that paid working week is also shrinking:

Workers in the UK are working the equivalent of a week's work less a year than they did 20 years ago, new figures have revealed.

According to the Office for National Statistics, the average worker in the UK worked exactly 31 hours a week in the final few months of 2016. This is 0.6 hours per week fewer than the equivalent figure in 1998.

Over the course of a year this is the equivalent of 31.5 hours, roughly one extra week.

That working week has been shrinking over the near century since Keynes wrote as well. Which is all as we'd expect it to be. Our starting assumption is that humans try to maximise their utility and some amount of leisure adds to that, as does some measure of income or ability to purchase worldly goods. This is also the idea which gives us the substitution effect which makes up one half of the Laffer Curve argument. As people become generally richer we would expect them to take some amount of that higher income in more leisure therefore.

The same logic can also be run backwards. That people are taking more voluntary leisure can be used as evidence that we are all getting richer. For we are achieving greater utility, the only measure of wealth that actually matters.