This review of the literature on the 2007-2009 crisis discusses the precrisis conditions, the crisis triggers, the crisis events, the real effects, and the policy responses to the crisis. The precrisis conditions contributed to the housing price bubble and the subsequent price decline that led to a counterparty-risk crisis in which liquidity shrank due to insolvency concerns. The policy responses were influenced both by the initial belief that it was a market-wide liquidity crunch and the subsequent learning that insolvency risk was a major driver. I suggest directions for future research and possible regulatory changes.

This paper develops a theory of strategic information disclosure with disagreement. Managers of firms are voluntarily communicating subjective information, and prior beliefs about the strategy to maximize project value are rational but heterogeneous, potentially generating fundamental disagreement. Three main results are derived. First, not all firms disclose (subjective) information about strategy. Second, more valuable firms, and those whose strategies investors are more likely to agree with, disclose less information in equilibrium. Third, improved corporate governance leads to lower executive compensation and less information disclosure. An implication of the analysis for banks is that greater strategic information disclosure may increase the probability of bank runs—banks may choose to be opaque because transparency makes them fragile.

This paper develops a theory that explains why financial crises follow profitable lending booms. When agents exhibit the “availability heuristic” and there is a long period of banking profitability, all agents—banks, their investors, and regulators—end up in an “availability cascade,” overestimating bankers' risk-management skills and underestimating the probability that observed outcomes are due to good luck. Consequently, banks profitably invest in riskier assets. Subsequently, if a public signal reveals that outcomes are luck-driven, investors withdraw funds, liquidity evaporates, and a crisis ensues. A loan resale market improves liquidity but increases the probability of a crisis.

We develop a theory of optimal bank leverage in which the benefit of debt in inducing loan monitoring is balanced against the benefit of equity in attenuating risk shifting. However, faced with socially costly correlated bank failures, regulators bail out creditors. Anticipation of this generates multiple equilibria, including one with systemic risk in which banks use excessive leverage to fund correlated, inefficiently risky loans. Limiting leverage and resolving both moral hazards—insufficient loan monitoring and asset substitution—requires a novel two-tiered capital requirement, including a “special capital account” that is unavailable to creditors upon failure.

An enduring puzzle is why credit rating agencies (CRAs) use a few categories to describe credit qualities lying in a continuum, even when ratings coarseness reduces welfare. We model a cheap-talk game in which a CRA assigns positive weights to the divergent goals of issuing firms and investors. The CRA wishes to inflate ratings but prefers an unbiased rating to one whose inflation exceeds a threshold. Ratings coarseness arises in equilibrium to preclude excessive rating inflation. We show that competition among CRAs can increase ratings coarseness. We also examine the welfare implications of regulatory initiatives.