Well, yes Sir Simon, but how do we calculate this?

Simon Jenkins is reviving the notion that clever people like himself, those Great and the Good, can tell all of the rest of us how to live our lives. His particular example is supermarkets but it could be anything at all really, given the proclivities of some to tell other people what to do. We went from that High Street thing, to supermarkets, to out of town supermarkets and perhaps now to online sales:

Land is Britain’s most precious resource. The point of planning is to economise its usefulness.

We'd argue a bit there, Britain's most precious resource is Britons. Their, our, accumulated knowledge, labour and the accumulated labour (also known as capital) handed down from our forefathers. But that aside, yes, of course, we wish to create the maximum economic benefit from whatever resources we have (and that does not mean just money, of course not, we're talking utility here).

At which point we've got to ponder, well, how do we do that maximisation? And the truth is no one knows. That's why we cannot plan. Should someone, in the 1980s, when considering a planning application for a supermarket have predicted the rise of the internet, Amazon and Ocado? Could they have done so? In the 1990s?

Yes? No?

If not, then it couldn't have been planned for, could it?

At present, smart planning ought to be thinking ahead of the boom in online shopping. What mistakes might there be in pandering to its gargantuan appetites? What are the implications of every street jammed with home delivery lorries? What of every suburb blighted with distribution centres, supplied by giant hangars littering every motorway?

The correct answer here is "we dunno". Nor do you and nor does anyone else. We're all just going to have to suck it and see. Or, as we might put that a little more formally, allow the market to sort it all out. We consumers will work out which of the various options we ourselves prefer, those who cater to our desires will prosper and we'll end up with a system that might not exult entirely everyone but which does the best to provide aggregate human utility that can be managed at this stage of technological progress.

And yes, that does mean that Sir Simon and his ilk don't get to plan it all for us. Exactly what annoys them all so much of course.