As a mild econo-sceptic, I enjoyed James Buchanan's short essay, Economists Have No Clothes:
Economists do not really understand what they are doing as they seem forced to make efforts to control aggregate variables that are not controllable in any direct sense. For example, the rate of employment (or unemployment) cannot readily be shifted by governmental mandate. At best, small and peripheral changes may be made while the emergent aggregate generated by the working of the large and complex economy remains stubbornly immune, or worse, to wrongly conceived reform efforts.
Hat-tip: Tyler Cowen.“
How do markets work? Standing alone, this is an inappropriate and unanswerable question. It must be replaced by the question: How do markets work under this or that set of constitutional and institutional constraints? Economists’ scientiﬁc expertise can be brought to bear on the predicted effects of alternative sets of constraints. The relevant question is not that of asking how this or that end-state or outcome may be put in place through possible collective or political action. The question becomes, instead, how can this or that set of constraints be predicted to operate so as to allow the generation of an order that meets certain criteria of desirability? The difference between the two methodological stances may appear minor, but much ill-advised effort might be avoided if economists would recognize the limits of their own discipline.