Lending Booms, Smart Bankers, and Financial Crises

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.