Good questions. It has to be a basket of prices across industries to eliminate undue influence of single factors like an oil shortage. Better to keep oil out entirely. Things like locally produced food are a much better indicator of money supply as there are many suppliers across the whole country and not subjected to whims. 10,000 farmers aren't suddenly going to get up one morning and collectively decide to limit the amount of wheat or what. Yes the money supply has to be adjusted after the fact so it plays a bit of catch up. Interests rates are usually adjusted every 3 months or so IIRC. I'll do some research on this. I think in today's hyper digitized economy it's actually possible to get a much better bird's eye view of the economy that the old fashioned ways of people born last century. Amazone would probably do a better job as issuing a stable currency that any government.