Commentary about the credit crisis has identified a wide range of culprits: faulty risk models (both at banks and at rating agencies) that relied on historical frequencies during a time of changing practice; faulty underwriting driven by the skewed incentives of the new originate-to-distribute model; faulty regulatory oversight based on imagined effectiveness of private policing of counterparty risk; faulty monetary policy that kept interest rates too low for too long, so sparking a credit-fueled asset bubble that was bound to collapse. Deeper causes have also been suggested: a capital adequacy regulatory regime that did not encompass the burgeoning shadow banking system; a pattern of global imbalances that was sustained in the short run by sending the best dollar assets (Treasuries and GSEs) to Asia, leaving a vacuum on the balance sheets of American and European financial intermediaries that was filled by the new untested products of structured finance.