Economics has limited application because its explanatory model cannot account for all the social and behavioral idiosyncrasies of the community or the individual. From Richard Bookstaber’s The End of Theory:

It is a deeply held conviction within economics that our world can be reduced to models that are founded on the solid ground of axioms, plumbed by deductive logic into rigorous, universal mathematical structures. Economists think they have things figured out, but our economic behavior is so complex, our interactions are so profound that there is no mathematical shortcut for determining how they will evolve. The only way to know what the result of these interactions will be is to trace out their path over time: we essentially must live our lives to see where they will go. There is no formula that allows us to fast-forward to find out what the result will be. The world cannot be solved; it has to be lived.