I'm not capable of following the mathematical argument, but I'll take your word. As for practical measurement... Colman mentions unemployment, but let's go straight to employment, annual hours worked, where there are different measurement tools, concepts, and calculations, making international comparisons impossible (says OECD), and don't let's go on to output, productivity...
Possibly practical decisions can be made within one country, much like a businessman who doesn't understand his balance sheet, or has reason to know it's bs anyway, can still have a canny sense of how to run his business. But it's seat-of-pants flying... And may end in a nosedive.
The pretension to accurate drawing of a universal picture seems to have taken a knock with the World Bank's China PPP announcement. But if you're right and it's Aristotelian physics, 40% or 4% yardstick error, what does it matter? When locusts move on, they leave nothing behind
That's exactly what Keynes was saying in The General Theory...
Nevertheless these difficulties are rightly regarded as 'conundrums'. They are 'purely theoretical' in the sense that they never perplex, or indeed enter in any way into, business decisions and have no relevance to the causal sequence of economic events, which are clear-cut and determinate in spite of the quantitative indeterminacy of these concepts. It is natural, therefore, to conclude that they not only lack precision but are unnecessary.
It is natural, therefore, to conclude
Does he go on to say that this natural logic is justified? When locusts move on, they leave nothing behind
(In my example, I assumed a businessman was better off understanding the balance sheet all the same...) When locusts move on, they leave nothing behind
