I just read a pretty good essay over at The Freeman, discussing the difference between what we can do and what we ought to do. Too often, people talk about what we ought to do before even considering if we can do it. The essay, appropriately enough is Ought Implies Can.
There are two parts I particularly liked. The first was on the problem of imperfect knowledge.
The economist David Prychitko once defined economics as “the art of putting parameters on our utopias.” And in a particularly insightful definition, Nobel laureate F. A. Hayek wrote that “The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design.” What both definitions suggest is that economics deals with the realm of the possible and in doing so demarcates the limits to what should be imaginable.
The author points out that this practice makes economists unpopular.
Economists are thus often seen as only knocking down the ideas of others without coming up with solutions of their own. There is some truth to this claim. That is how economists spend much of their time. But it’s an important function: showing why a proposed solution would only make matters worse is a valuable contribution to the broader process of solving the problem.
So, before you tell me that we ought to do it -- healthcare reform, for instance -- you first need to demonstrate that we can do it. Preferably in some level of detail.