This paper examines optimal policy in a macroeconomic model with collateral constraints. Binding collateral constraints yield inefficient competitive equilibrium allocations because they distort the optimal utilization of real resources. I identify the set of policy instruments that can be used...

An asset bubble relaxes collateral constraints and increases borrowing by credit-constrained agents. At the same time, as the bubble deflates when constraints start binding, it amplifies downturns. We show analytically and quantitatively that the macroprudential policy should optimally respond...

An asset bubble relaxes collateral constraints and increases borrowing by credit-constrained agents. At the same time, as the bubble deflates when constraints start binding, it amplifies downturns. We show analytically and quantitatively that the macroprudential policy should optimally respond...

We study optimal long-run capital taxation in a closed economy with heterogeneity in agents' time-discount factors where borrowing is allowed but restricted by a collateral constraint. Financial frictions distort intertemporal optimization margins and the tax system serves a dual role: first, it...