Policy Rules and Monetarist Arithmetic

This note demonstrates the existence of an important equilibrium path overlooked in the literature on monetarist arithmetic. Pleasant monetarist arithmetic is possible when the interest‐elasticity of money demand exceeds unity. In this case, tight money may lead to a transitory increase in seigniorage, the retirement of government debt, and lower inflation in both the short run and the long run. The set of equilibrium paths is sensitive, however, to the form of the policy rule. Pleasant monetarist arithmetic is not an equilibrium if the policy rule fixes the share of the fiscal deficit financed by seigniorage. Both pleasant monetarist arithmetic and the tight‐money paradox are equilibrium paths when the government's commitment to low money growth is conditional on inflation remaining below its previous level.