Here's a conjecture: the rise of "post-truth" politics (defined by the OED as a process whereby "objective facts are less influential in shaping public opinion than emotional appeals") is in part the product of deindustrialization.

What I mean is that in manufacturing, facts defeat emotions and opinions. If your steel cracks, or your bottles leak or your cars won't start, all your hopes and fancy beliefs are wrong. Truth trumps opinion.

Contrast this with sales occupations. In these, opinion beats facts. If customers think a shit sandwich is great food, it'll sell regardless of facts. And conversely, good products won't sell if customers think they're rubbish. Opinion trumps truth.

(Finance is a mix of these. In trading and asset management, beliefs are constantly defeated by cold hard facts. In asset gathering, sales and investor relations, however, bullshit works.)

Isn't it therefore possible that a shift from manufacturing to other occupations will contribute to a decline in respect for facts and greater respect for opinions, however ill-founded? In 1966 - when employment in UK manufacturing peaked - 29.2% of the workforce were in manufacturing. This meant that millions more heard tales from fathers, husbands and friends about how brute facts had fouled up their day. A culture of respect for facts was thus inculcated. Today, however, only 7.8% of the workforce is in manufacturing and many more are in bullshit jobs. This is an environment less conducive to a deference to facts.

How people live shapes how they think. A world in which many people work in manufacturing might, therefore, have different beliefs to one in which they don't.

You might object here that the UK has been deindustrializing since the 60s, so why should "post-truth" only have emerged so recently?

In part, it didn't. Lies are as old as politics. Saatchi and Saatchi's famous 1979 poster "Labour isn't Working" was a picture not of jobless workers but of Tory party volunteers. And Kelvin Mackenzie's Sun did in the 80s pretty much what Breitbart does now.

Also, culture can persist long after the economic circumstances which created it fade away.

And also, it is only recently that the technologies have emerged to facilitate a post-truth media. Breitbart or the Canary probably could not have emerged in a time when you needed to spend millions on printing presses and when the established press had strong brand loyalty.

So far, so much conjecture. What sort of facts would support or disconfirm this?

I can think of two supportive facts. One is that post-truth politics seems (I might be wrong) to be less strong in countries where manufacturing still looms large in culture if not in economics, such as in Germany or Japan.

The other is that pre-industrial societies tend to have less scientific cultures than industrial ones. For example, in 17^th century England people believed some very strange things. It's a commonplace that the Industrial Revolution grew from the scientific revolution and Enlightenment. But mightn't the causality run both ways? Maybe the Industrial Revolution strengthened respect for facts and evidence, a respect that's declining in our post-industrial age.

Now, I stress all this is just a theory. Feel free to offer some discorroborative evidence. But it has a worrying implication. What I'm saying implies that post-truth politics isn't just a bad thing done by bad people and followed by silly ones. It might instead have a strong economic root and those who deny this and consider it merely a moral failing are guilty of what Phil calls structural naivete. If so, then we might be stuck with post-truth politics for a long time.