The author Michael Lewis was asked on CNBC last week about the widespread notion that blame for the panic of '08 should be laid at the feet of greedy Wall Street executives, and the corollary that some of them should be in jail. Was the crash the result of criminal behavior or cluelessness?

Lewis replied that while he is no expert on securities law, in all his reporting on the subject, he never encountered anything that made him think somebody ought to go to jail for it, and maybe that was one problem: The excess and recklessness were legal.

At any rate, most Americans still carry the sour feeling that those responsible for the debacle are walking free. Yet that feeling is a bit misplaced, leaving out the much more significant role of the government. After all, Wall Street greed is almost redundant.

Cluelessness isn't a crime, at least not yet. Let's remember that most of the securities that blew up had triple-A ratings, which tells you that Wall Street execs didn't have a monopoly on cluelessness. Rating agencies like Moody's and S&P were involved, too.

Politicians of a certain stripe, including President Obama, are ever eager to supply a simple explanation to those hungering for one. So they refer vaguely to the "policies that caused the problem," without saying what those policies might be. Or they blame the whole thing on "deregulation," without mentioning a specific deregulatory effort.

The repeal of a Depression-era law that separated commercial from investment banking is sometimes mentioned, and here there's a measure of plausibility. That helped make big banks bigger and more likely to threaten other banks in a crash. But even this seems insufficient.

In 2008, it was the failure of Bear Stearns, followed by Lehman Bros., that triggered the cascade. Yet both were investment banks. They had no commercial deposits and were unaffected by the repeal of that law.

Of the books I've read dealing with the crash, the one that got closest to the heart of the rot was Reckless Endangerment, by Gretchen Morgenson and Joshua Rosner. The debacle originated, they wrote, in the widespread belief in Washington — not on Wall Street — that "every living breathing citizen should own a home."

In the effort to extend "affordable housing" further and further down the income scale, credit standards became so debased that people who should not have been buying homes at all were signing up for manipulative, unaffordable mortgages.

Why did mortgage originators make those loans to begin with? To a great extent, it was because they could get the bad paper off their books by selling it to the government-affiliated mortgage giants, Fannie Mae and Freddie Mac. To make matters worse, Fannie and Freddie then put taxpayers on the hook by guaranteeing payment.

This wasn't the first time government efforts to boost home ownership among low-income families had unforeseen consequences. The Section 235 program of the late '60s decreed that housing credit should be made available to poor renters, with little regard for their creditworthiness or financial capacity to maintain a home.

The law created many new homeowners, but only briefly. Facing the need to replace a roof or furnace, many simply abandoned their homes. Section 235 decimated our urban housing stock, not to mention the credit of the people it was intended to help.

There are many lessons here, but one concerns the risk of excessively subsidizing things held to be beneficial, like home ownership. Washington can't know the "correct" degree of home ownership any more than the "correct" proportion of college attendance — which is perhaps why so many now worry that the next bubble to pop will be higher-education debt.

E. Thomas McClanahan is a member of the Kansas City Star's editorial board.