From Russ Roberts.
Keynes saw economics ideas influencing policy. But maybe it is policy that influences economics. So as the world becomes more interventionist, the economists respond by finding arguments that rationalize that policy. (I am sure I’m not the first person to suggest this. Feel free to share references in the comments.)
…Obviously, this is not the whole story. Keynes was right–good ideas are powerful. Economists aren’t just affected by public opinion, they affect it in turn. But I do think our profession (like journalists) have a view of ourselves that is quite romantic–we see ourselves as truth-seekers. Well, yes, there is an element of truth-seeking in what we do. But it’s not the only factor.
I believe it helps to think in terms of two uses for reasoning. There is motivated reasoning, which is aimed at rationalizing one’s own actions and those of one’s favored group. And there is constructive reasoning, which is aimed at seeking the truth. The existence of motivated reasoning is well established in the literature on psychology and political beliefs. The existence of constructive reasoning is something that I take on faith.
It is tempting to say that I engage solely in constructive reasoning, while other people engage in motivated reasoning. Of course, the odds that this is the case are not very high.
In fact, I think that in contemporary America we are highly tribal in our political beliefs. Think of my three-axis model. If you make an argument that rationalizes the views of those who share your ideology and puts down the views of those with a different ideology, you raise your status within your tribe. If you do the opposite, you lower your status within your tribe. So once you become embedded in a tribe, your reasoning tends more and more toward motivated reasoning.