"Economics is all about prediction. It came into existence and continues to be maintained with all sorts of lavish funding, because people with money want to know what other people with money are likely to do. As a result, it is also a discipline that, more than any other, tends to participate in the world it describes. That is to say, economic science is concerned with the behavior of people who have some familiarity with economics - either ones who have studied it or at the very least are acting within institutions that have been entirely shaped by it. Economics, as a discipline, has almost always played a role in defining the situations it describes. Nor do economists have a problem with this; they seem to feel it is quite as it should be."
David Graeber Toward an Anthropological Theory of Value - The False Coin of Our Own Dreams (2001) p.7