Can the world be made safe for the return of securitizations?

That is a question of great importance to those like John C. Dugan, the comptroller of the currency, who say they believe that the banking system on its own is unlikely to have the ability to provide enough credit to sustain an economic recovery in the United States.

“We need a vibrant, credible securitization market to help fund the real economy going forward,” Mr. Dugan said this week. He was preaching to the choir  a meeting of the American Securitization Forum  but it is an opinion widely held in financial markets.

It is possible to question that thesis. Securitization grew as a way for banks to get around capital rules, not because of any profound desire by investors for such assets or any real unwillingness by banks to make the loans. But since it was more expensive to hold capital against the risk if the loans were not securitized, they were securitized. That also opened the market to new players, who neither wanted to, nor could amass, the capital to hold onto loans.

Together, those developments undoubtedly made mortgage loans less expensive for borrowers. That was welcome to politicians and to regulators, who wrongly thought that securitization had moved a lot of risk outside the banking system.