Provides an overview of the subprime mortgage securitization process and the seven key informational frictions that arise. Discusses the ways that market participants work to minimize these frictions and speculate on how this process broke down. Continues with a complete picture of the subprime borrower and the subprime loan, discussing both predatory borrowing and predatory lending. Presents the key structural features of a typical subprime securitization, documents how rating agencies assign credit ratings to mortgage-backed securities, and outlines how these agencies monitor the performance of mortgage pools over time. The authors draw upon the example of a mortgage pool securitized by New Century Financial during 2006. Illustrations.