Macro-prudential taxation in good times

We analyze the optimal macroprudential policy under the presence of persistent permanent shocks, which convey information about future growth. In this context, crises are characterized by long periods with positive shocks that eventually revert, rendering the collateral constraint binding and triggering deleveraging. In this environment it is optimal to tax borrowing during good times, and let agents act freely leaving the allocations undistorted, including borrowing and lending, when the economy reverts to a bad state. We contrast our findings to the case of standard shocks to the level of income, where it is optimal to tax debt in bad times, when agents need to borrow the most for precautionary savings motives. Also, taxes are used much less often and are around one-tenth of those under level shocks.