Need for (the Right) Speed: the Timing and Composition of Public Debt Deleveraging

This paper studies the optimal path for public debt deleveraging in a heterogeneous agents framework under incomplete financial markets. My analysis addresses two questions. What is the optimal fiscal instrument the government needs to use to reduce public debt? What is the optimal speed of public debt deleveraging? The main finding is that public debt should be reduced quickly and by cutting public expenditure. If the fiscal authority is forced to use income taxation instead, public debt deleveraging needs to be slow. Independently of fiscal instruments, the economy may end up in a liquidity trap. I show that, in my model, the zero lower bound has a redistributive effect. If the liquidity trap is very persistent, it can reallocate resources from financially constrained agents to financially unconstrained ones. Due to this mechanism, a very slow public debt reduction achieved by increasing income taxation is very costly in terms of aggregate welfare.