Rodrik on Economic Models

There is an an excellent piece by Dani Rodrik on economic methodology at Project Syndicate:

Economics is not the kind of science in which there could ever be one true model that works best in all contexts. The point is not “to reach a consensus about which model is right,” as Romer puts it, but to figure out which model applies best in a given setting. And doing that will always remain a craft, not a science, especially when the choice has to be made in real time.

The social world differs from the physical world because it is man-made and hence almost infinitely malleable. So, unlike the natural sciences, economics advances scientifically not by replacing old models with better ones, but by expanding its library of models, with each shedding light on a different social contingency.

Or, as Keynes put it, "Economics is the science of thinking in terms of models joined to the art of choosing models which are relevant to the contemporary world." 

Rodrik goes on to discuss Borges' story "On Exactitude in Science" - a parable about cartographers who make a map on the same scale as the world it was meant to represent.  This story, which was our reading for Econ 110 yesterday, illustrates the point that "more realistic" isn't necessarily better.