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...

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...