Credit Constraints and Self-Fulfilling Business Cycles

We argue that credit constraints not only amplify fundamental shocks, they can also lead to self-fulfilling business cycles. We study a model with heterogeneous firms, in which imperfect contract enforcement implies that productive firms face binding credit constraints, with the borrowing capacity limited by expected equity value. A drop in equity value tightens credit constraints and reallocates resources from productive to unproductive firms. Such reallocation reduces aggregate productivity, further depresses equity value, generating a financial multiplier. Aggregate dynamics are isomorphic to those in a representative-agent economy with increasing returns. For sufficiently tight credit constraints, the model generates self-fulfilling business cycles.