How should monetary and fiscal policy react to adverse financial shocks? If monetary policy is constrained by the zero lower bound on the nominal interest rate, subsidising the interest rate on loans is the optimal policy. The subsidies can mimic movements in the interest rate and can therefore...

We consider standard cash-in-advance monetary models and show that there are interest rate or money supply rules such that equilibria are unique. The existence of these single instrument rules depends on whether the economy has an infinite horizon or an arbitrarily large but finite horizon.