How did economists get it so wrong?

The magnitude of the current financial crisis reflects the failure of an economic and regulatory philosophy that proved increasingly influential in policy circles during the past three decades. This philosophy, guided more by theory than historical experience, held that private financial institutions not insured by the government could be largely trusted to manage their own risks—to regulate themselves. The crisis has suggested otherwise, particularly since several of the least regulated parts of the system (including non-bank mortgage originators and the major broker-dealer Bear Stearns) were among the first to run into trouble. Former Federal Reserve Chairman Alan Greenspan acknowledged in October 2008, “Those of us who have looked to the self-interest of lending institutions to protect shareholders’ equity, myself included, are in a state of shocked disbelief.”