This paper shows that collateralized short-term debt, although privately optimal for reducing borrowers’ risk-taking incentives, can induce fragility (multiple equilibria). Despite sequential-service property being absent in collateralized debt, such as repurchase agreements, a systemic run can arise, featuring large increases in default risks, fire-sale discounts of collateral, cost of credit, and amount of credit rationing. Asset price guarantees, leverage caps, and central clearing promote stability and welfare. Using global games techniques, I show that a systemic run is more likely in bad times, and a large enough asset price guarantee reduces run risks.

Does securitization distort the foreclosure decisions of non-performing mortgages? In a model of mortgage-backed securitization with an endogenous foreclosure policy, we find that the securitizing bank adopts a tougher foreclosure policy than the first-best, despite resulting in higher loan losses. This is optimal because foreclosure mitigates the adverse selection problem in securitization by making the optimal security, a risky debt, less information-sensitive. We further show that policies that limit mortgage foreclosure would discourage the bank’s ex ante screening effort, reducing the quality of securitized mortgages. Our model yields novel testable predictions on the effect of mortgage securitization on foreclosure rates, loan performance, and mortgage servicing.

We analyze a tractable rational expectations equilibrium model with margin constraints. We argue that constraints affect and are affected by informational efficiency, leading to a novel amplification mechanism. A decline in wealth tightens constraints and reduces investors’ incentive to acquire information, lowering price informativeness. Lower informativeness, in turn, increases the risk borne by financiers who fund trades, leading them to further tighten constraints faced by investors. This information spiral leads to (a) significant increases in risk premium and return volatility in crises, when investors wealth declines, (b) complementarities in information acquisition in crises, and (c) complementarities in margin requirements.