Pretense of Knowledge

Russ this excellent essay in today's Wall Street Journal.  Here are the final three paragraphs:

If economics is a science, it is more like biology than physics. Biologists try to understand the relationships in a complex system. That's hard enough. But they can't tell you what will happen with any precision to the population of a particular species of frog if rainfall goes up this year in a particular rain forest. They might not even be able to count the number of frogs right now with any...