We study optimal fiscal and monetary policy in an environment where explicit frictions give rise to valued money, making money essential in the sense that it expands the set of feasible trades. Our main results are in stark contrast to the prescriptions of earlier flexible-price Ramsey models....

We study the efficiency properties of a dynamic, stochastic, general equilibrium, macroeconomic model with monopolistic competition and firm entry subject to sunk costs, a time-to-build lag, and exogenous risk of firm destruction. Under inelastic labor supply and linearity of production in...