What a relief to see the sign at the Subway restaurant: “We have tomatoes, approved by the FDA.” In the event, I didn’t want tomato on my sandwich, but it’s good to know the government is looking out for me.

I did take a big chance by asking them to load up on salad spinach. As New York Times humor columnist Paul Krugman put it last year, “Yesterday I did something risky: I ate a salad.” Rim shot, please.

Krugman’s concern then was with E. coli bacteria, which had been found on some spinach. One person died as a result of that contamination. Subway was worried about tomatoes because of a salmonella outbreak that has made at least 167 people sick.

No doubt some will join Krugman, one of the country’s most famous sufferers of Bush Derangement Syndrome, in blaming this latest misfortune on the president.

“Without question, America’s food safety system has degenerated over the past six years,” Krugman asserted. How could he be so sure? Because there haven’t been any new federal regulations. “What we do know is that since 2001 the F.D.A. has introduced no significant new food safety regulations except those mandated by Congress,” he wrote.

And that, in a nutshell, is the problem: For many people today any problem, no matter how large or small, calls for federal intervention. In this view, as long as Washington is passing new regulations -- i.e. “doing something” -- it’s doing its job. Few stop to wonder if new regulations are helpful, or even necessary.

Consider the housing crisis.

In recent months, the collapse of the subprime lending market has given politicians plenty of chances to insist that Washington ought to “do something.” But as blogger Megan McArdle pointed out at theatlantic.com, nobody’s laid out a regulatory plan that would have prevented the mortgage mess. “There’s no real evidence that the problem in the housing market was supply-side, rather than demand-side, fraud,” she notes.

In fact, it’s the free market that tends to keep companies honest, not the government.

Banks and other financial institutions try to make money -- that’s how they stay in business. “Profit, in this case, [is] a pretty strong motive for doing what we want them to do: avoiding catastrophic failures. That’s why I think that a powerful regulatory body is only an unquestionable win if you have some reason to think that it will be smarter than the banks,” McArdle writes. And there’s no reason to expect financial geniuses will line up to work as regulators at government salaries. Continued...