I'm going through Morgenstern's book right now, and it's really good. It's the first economic text I've ever seen that tries to address, in a systematic and no-nonsense way, the crucial question of whether various sorts of numbers routinely used by economists (and especially macroeconomists) make any sense at all. That this book hasn't become a first-rank classic, and is instead out of print and languishing in near-total obscurity, is an extremely damning fact about the intellectual standards of the economic profession. I've also looked at some other texts by Morgenstern I found online. I knew about his work in game theory, but I had no idea that he was such an insightful contrarian on the issues of economic statistics and aggregates. He even wrote a scathing critique of the concept ot GNP/GDP (a more readable draft is here). Unfortunately, while this article sets forth numerous valid objections to the use of these numbers, it doesn't discuss the problems with price indexes that I pointed out in this thread.

realitygrill: [...] Could you please list some examples? Aside from Austrians and a few other fringe contrarians, I almost always see economists talking about the "real" figures derived using various price indexes as if they were physicists talking about some objectively measurable property of the universe that has an existence independent of them and their theories. [...] Thanks for the pointer! Just a minor correction: apparently, the title of the book is On the Accuracy of Economic Observations. It's out of print, but a PDF scan is available (warning -- 31MB file) in an online collection hosted by the Stanford University. I just skimmed a few pages, and the book definitely looks promising. Thanks again for the recommendation!