And those in such self employment are making pennies - it's a common enough comment being made about that rise in self employment since the crash. It's one of those things which could even be true, therefore one of those things we need to test:

Britain's public finances were back in the black last month as a surge in self-employed workers' tax payments boosted the Treasury's coffers.

The surplus of £184m is the first in any July since 2002, figures from the Office for National Statistics (ONS) show.

Economists had expected the Treasury to record a deficit of £1bn, up from the £308m additional borrowing in July 2016. But instead rising self-assessment tax receipts gave the Chancellor a boost.

The July figures show that payments of self-assessed income tax increased by 11pc from the same month of last year to £8bn, the highest level since records began in 1999.

Ah, so, having tested it we find that it's one of those things which turns out not to be true. Ah well.

Which is an interesting little reminder of a deeper point. There are many things which could be true in something as complicated and chaotic as the economy of 65 million people. This could be causing that, it might actually be doing that other over there. A priori we're really not sure, as here, theory isn't good enough to tell us whether self employment is a push matter, people not being able to find anything else, or a pull, people doing it because it's better. We just have to wait and find out.

Which runs us smack into Hayek's wall about the pretence of knowledge. Theory isn't good enough, only facts can aid us in deciding. But facts are difficult to come by and they're certainly not available beforehand, only in fragments and afterward. Thus we cannot go around planning and in detail simply because the information we need isn't there to predict that future.