I think the crisis came about primarily because people of all stripes did novel, complex and dangerous things, in greater amounts than ever before. In the world of investing, for instance, people made excessive use of borrowed money — “leverage” — and committed too much capital to illiquid investments. It all happened because people believed too much, worried too little and thus took too much risk.
Worry and its relatives, distrust, skepticism and risk aversion, are the essential ingredients for a safe financial system. To paraphrase a saying about the usefulness of bankruptcy, I think fear of loss is to capitalism as fear of hell is to Catholicism. Worry keeps risky loans from being made, companies from taking on more debt than they can service, portfolios from becoming overly concentrated, and unproven schemes from turning into popular manias. When worry and risk aversion are present as they should be, investors will question, analyze and act prudently. Risky investments either won’t be undertaken or will be required to provide adequate compensation in terms of anticipated return.