I apologize for not sticking it out until the end of the article, but it got really painful about a third of the way through.<p>I am tempted to save this and put it under a file titled something like "why scientists should not be economists" but I'm afraid it's a little too involved for that purpose.<p>I mean no disrespect to the author: these all seem like good and reasonable questions. To understand why this form of analysis does not work is to cut to the heart of what the difference between economics and hard empirical sciences. I will give a couple of examples, but I fear that folks who missed it the first time around will not get it this time.<p>First, note that no matter what period in human history this conversation occurred, it would follow the same pattern. "Here is a chart of the rate of fishing from the pond near our Roman village. Certainly catastrophe awaits us in just a few years", or one that actually occurred, "Population growth will stagnate and we will have famine when the 1900s come. Why? Because we will have ran out of grazing land for all the horses we will need"<p>Growth lines can't continue forever. Seems obvious. Yet somehow it always turns out the thing you were measuring wasn't the important thing all along. Sure, you can only fish so much -- but there are other ponds. Yep, can't have that many meadows -- yet meadows aren't a constraining factor.<p>The reason why such analysis fails is that science is always seeking a constrained and known system. Given controlled conditions, the falsifiability and reproducibility of science says that given these inputs, these outputs are likely to occur. Economics, because it deals with what people want, is under no such constraints. Let's say you give everyone on the planet all the food, shelter, and healthcare they need. End of money, right? Nope. People would trade Justin Bieber concert tickets, or autographs of Elvis Presley. People always want stuff they don't have, and they always like trading for it. That's economics.<p>If economic systems were the same as physical systems, wow, we'd have a lot of physicists who have made fortunes playing the stock market. We do not.