I give necessary and sufficient conditions under which interest-rate feedback rules eliminate aggregate instability by inducing a globally unique optimal equilibrium in a canonical New Keynesian economy with a binding zero lower bound. I consider a central bank that initially keeps interest...

We propose a new interest rate rule that implements the optimal equilibrium and eliminates all indeterminacy in a canonical New Keynesian model in which the zero lower bound on nominal interest rates (ZLB) is binding. The rule commits to zero nominal interest rates for a length of time that...