From an excellent post by Barbara Kiviat (pay close attention to the last sentence):
There’s been some interesting discussion in response to my earlier post about why we expect too much from economists, although a lot of the comments miss my larger point. What I was trying to say is that economics might not entirely be up to the task of explaining what we generally consider to be economic phenomena because we are overconfident about what the discipline has the ability to account for. You might call this the Freakonomics Fallacy. Whatever it is in the world we are trying to explain—crime, climate change, test scores—economics has the answer.
If this isn’t in fact true, then why would we think it? Again, to underscore a part of my earlier argument that I probably didn’t make forcefully enough: we think economics has all the answers because economics has become our major mode of understanding the social world around us. Charities are social businesses. Policy makers are cost-benefit analyzers. Education is a market.
This has not always been the case. In earlier eras, we were often more likely to understand human behavior and social dynamics through other prisms, such as political science, sociology, psychology, anthropology or biology. Indeed, for better or for worse, many of these fields took a turn being the dominant social science. I’m not saying that one frame gives a more accurate or useful picture of the world than another. Just that each leads to a different way of understanding why things happen the way they do because each comes with its own set of assumptions and simplifications.
You can see my thoughts on the subject here.