You’ve heard of “gateway drugs.” What about “gateway capitalism”?

The mayor of Clayton, California, apparently believes that two little girls selling zucchinis and melons by the roadside is the start of something bad.

The city cracked down on Katie and Sabrina Lewis’s veggie stand. Mayor Gregg Manning defended the bust, saying that “They may start out with a little card-table and selling a couple of things, but then who is to say what else they have. Is all the produce made there, do they make it themselves? Are they going to have eggs and chickens for sale next?”

Heavens! Capitalism run amok! Streetside vendors are to be allowed only when city governments run the show, as in the growing movement to establish old-fashioned day-markets. You know, Saturday Markets and Sunday Markets and the like.

But veggie stands, like dreaded lemonade stands, are illegal in Clayton.

You can understand the concern, I guess: Traffic problems. This police operation started off on one complaint. But most neighbors defend the stand, saying that traffic was never a problem.

So now 11-year-old Katie has gotten political. She circulated a petition to reopen the stand, and has lots of signatures. Best of luck to Katie and Sabrina, but I am afraid that the lesson you’ll really be learning isn’t about capitalism at all. It’s about bureaucracy.

And an awful void of common sense.

This is Common Sense. I’m Paul Jacob.

Even the most careful athlete sometimes pulls a muscle. Does that mean that vigorous and sometimes even risky exercise is more dangerous than being a cordoned and cosseted couch potato?

Many of the gendarmes who oversee America’s playgrounds seem to think so. I don’t know how real the so-called “epidemic” of obesity is. (Is the fat infectious?) But it wouldn’t surprise me if kids banned from playing one “dangerous” game after another tend to accumulate more flab than when they were rambunctiously running around like they always used to do.

Even playing tag is outlawed in some places. Along with cops and robbers, monkey bars, and sliding into third base. Playground mats laid down to break possible falls are the latest terror. The sun sometimes makes them hot, and barefooted kids can burn their feet.

Playground activists are in an uproar over this latest bogus crisis. When are the canopies going up?

Philip Howard, the author of The Death of Common Sense: How Law is Suffocating America, says we’re teaching kids to be flabby in more ways than one. He notes that scrapes and bruises are one way “children learn their limits, and the need to take personal responsibility.”

Life is an inherently risky venture. You don’t learn to cope with those risks if you are never allowed to take even modest ones. And that’s dangerous.

This is Common Sense. I’m Paul Jacob.