We propose a theory to explain why, and under what circumstances, a politician endogenously gives up rent and delegates policy tasks to an independent agency. We apply this theory to monetary policy by extending a stochastic general equilibrium model. This model provides a theory of central bank independence that is unrelated to the standard time inconsistency problem which underlies all formalized theories of central bank independence. We derive five key predictions of the model and show that they are broadly consistent with the data. Finally, we show that while instrument independence of the central bank is desirable, goal independence is not. It is a general principle of human nature, that a man will be interested in whatever he possesses, in proportion to the firmness or precariousness of the tenure by which he holds it; will be less attached to what he holds by a momentary or uncertain title, than to what he enjoys by a durable or certain title; and, of course, will be willing to risk more for the sake of the one, than for the sake of the other."Hamilton (1788), Federalist Paper 71: The Duration in Office of the Executive "Many governments wisely try to depoliticize monetary policy by, for example, putting it in the hands of unelected technocrats with long terms of office and insulation from the hurly-burly of politics" (emphasis added) Blinder (1998), pp. 56-57.