We develop a new theory of information production during credit booms. Entrepreneurs need credit to undertake investment projects, some of which enable them to divert resources. Lenders can protect themselves from such diversion in two ways: collateralization, and costly screening that generates durable information about projects. In equilibrium, the collateralization-screening mix depends on the value of aggregate collateral. High collateral values make it possible to reallocate resources towards productive projects, but they also crowd out screening. This has important dynamic implications. During credit booms driven by high collateral values (e.g. real estate booms), economic activity expands but the economy’s stock of information on existing projects gets depleted. As a result, collateral-driven booms end in deep crises and slow recoveries: when booms end, investment is constrained both by the lack of collateral and by the lack of information on existing projects, which takes time to rebuild. We provide empirical support for the mechanism using US firm-level data.

We show that in a canonical model with heterogeneous entrepreneurs, financial frictions, and an imperfectly elastic supply of capital, a fall in the interest rate has an ambiguous effect on aggregate economic activity. In partial equilibrium, a lower interest rate raises aggregate investment both by relaxing financial constraints and by prompting relatively less productive entrepreneurs to invest. In general equilibrium, however, this higher demand for capital raises its price and crowds out investment by more productive entrepreneurs. When this reallocation is strong enough, a fall in the interest rate reduces aggregate output. A numerical exploration of the model suggests that this reallocation effect is quantitatively significant and—in response to persistent changes in the interest rate—stronger than the traditional balance-sheet channel. We provide evidence of the reallocation effect using U.S. firm-level data.