According to the Green Party, we should have a new economic target: leisure time. This, they argue, should be a formal measure of the economy. Our free time should be measured on an annual basis and be continually rising.

And why not? Leisure is great. Leisure is valuable. And so the more we have of it, the richer we must be. That, of course, is why we’ve historically taken some part of our increasing wealth in fewer working hours. We tend not to work 60 and 70-hour weeks as Britons did in the 19th century.

However, there are a couple of caveats. The first and most obvious is that this has to be voluntary. The easiest manner of increasing time off is to have a depression – by, for example, electing Jeremy Corbyn – and then few of us will have any work to do at all.

The second is that to achieve the leisure time the Greens want, we need to really open up the economy to globalisation, ditch recycling targets, stop trying to grow our own food and get serious about building nuclear plants. All the sort of policies the Greens themselves advocate increase the human labour we have to perform, leaving us with less leisure time.

Trade itself — and the specialisation and division of labour which produces the surplus to trade — is basic Adam Smith stuff. It’s what increases production and provides us with a higher physical standard of living with the same labour input – or, of course, the same one with lower.