Editor’s note: This is the first of a two-part series.

“According to a recent ‘Nightline’ program, none of the Wall Street executives who engineered the subprime debacle have been convicted on criminal charges. Why do you think that is?”

I think that the most obvious answer is the correct one: The authorities were not able to find sufficient evidence of criminal behavior in any of the cases they investigated (and they investigated many) because there wasn’t any to be found. Imprudent violations of firms’ own internal policies abounded, but such violations are not criminal.

Underlying your question, and implicit in the “Nightline” approach, is an assumption that the subprime debacle was engineered by a profit-hungry group of lenders and investment bankers who, for some unknown reason, decided to run amuck. Given that assumption, the failure to convict anyone must mean either that law enforcement has been co-opted or that all the suspected criminals who were investigated were clever enough to destroy all evidence of their misdeeds.