Negative interest rates remain a controversial policy for central banks. We study a novel signalling channel and ask under what conditions negative rates should exist in an optimal policymaker's toolkit. We prove two necessary conditions for the optimality of negative rates: a time-consistent...

Negative interest rates remain a controversial policy for central banks. We study a novel signalling channel and ask under what conditions negative rates should exist in an optimal policymaker’s toolkit. We prove two necessary conditions for the optimality of negative rates: a time-consistent...