Coordinating Monetary and Macroprudential Policies

This paper studies noncooperative games between a monetary authority and a macroprudential regulator whose objectives are a subset of those in the social loss function. The analysis is based on a New Keynesian model with a financial sector and a financial friction a la Gertler and Karadi (2011). When the friction affects the financing of all factors of production equally, macroprudential policy is shown to be a powerful additional tool, fully eliminating inefficiencies, regardless of the source of the shock and no matter whether the central bank and the regulator cooperate. But when trade-offs are present and policy is discretionary, the institutional arrangements become crucial. While coordination leads to higher welfare than a setting in which each authority takes the decision rule of the other as given (namely, the Nash equilibrium), our analysis shows that a noncooperative setting in which the macroprudential authority acts as a leader within the period can be superior to cooperation. Finally, our conclusions are unaffected by whether the macroprudential instrument affects funding costs or acts as a liquidity requirement.