Did the Banks Have to Commit Fraud?

Floyd Norris has an interesting piece discussing Citigroup's $7 billion settlement for misrepresenting the quality of the mortgages in the mortgage backed securities it marketed in the housing bubble. Norris notes that the bank had consultants who warned that many of the mortgages did not meet its standards and therefore should not have been included the securities.

Towards the end of the piece Norris comments:

"And it may well be true that actions like Citigroup’s were necessary for any ban...