Credit Traps and Macroprudential Leverage

We construct a macroeconomic model with overlapping generations to study credit traps—prolonged periods of stagnant real activity accompanied by low productivity, financial sector undercapitalization, and credit misallocation. Shocks to bank capital tighten banks' borrowing constraints causing them to allocate credit to easily collateralizable but low productivity projects. Low productivity weakens bank capital generation, reinforcing tight borrowing constraints, sustaining the credit trap steady state. Macroprudential policy to limit bank leverage can be welfare enhancing. In the presence of a credit trap, optimal leverage policy is countercyclical.