Financial crises are among the most destructive events in economic life, capable of erasing decades of wealth and prosperity in months. Understanding what triggers them — and why they consistently manage to surprise — is one of the most important and humbling questions in economics.
The most rigorous framework for understanding financial crises comes from Hyman Minsky's Financial Instability Hypothesis. Minsky argued, counter-intuitively, that stability is destabilising: long periods of economic calm encourage risk-taking, leverage, and complacency, sowing the seeds of the next crisis. In the good times, borrowers and lenders become increasingly confident. Credit standards loosen. Leverage rises. Asset prices inflate. Everyone believes the expansion will continue indefinitely.
Minsky identified three stages of lending behaviour. Hedge finance describes borrowers whose cash flows are sufficient to service both interest and principal — they are genuinely creditworthy. Speculative finance describes borrowers who can cover interest but must refinance the principal — they depend on continued credit availability. Ponzi finance describes borrowers who can cover neither interest nor principal from cash flows and depend entirely on asset price appreciation to repay — their entire position is contingent on prices continuing to rise.
Over a credit cycle, the composition shifts progressively from hedge to speculative to Ponzi. The tipping point — sometimes called the "Minsky moment" — occurs when something (a rate rise, a regulatory change, a specific default, a shock) causes confidence to reverse. Suddenly, credit contracts. Prices fall. Forced sellers flood the market. What looked like reasonable leverage in rising markets becomes crushing in falling ones.
This structural dynamic operates on top of specific triggers: oil price shocks (1973, 1979), asset price collapses (Japan 1990, US tech 2000, US housing 2007), currency crises (Asian crisis 1997), or exogenous shocks (COVID 2020). The trigger alone rarely causes a crisis — the crisis emerges when the trigger meets a financial system that has become dangerously leveraged and fragile during the preceding boom.