As someone who believes in liberty, my natural inclination is to defend a company like Wal-Mart from the usual attacks. You know, the company should pay its employees more (sure, just like all other companies, including libertarian think tanks!). Wal-Mart destroys local businesses (that is, enterprises which offer fewer choices but at higher prices, and whose customers cheerfully flee when given an alternative). The people most likely to attack Wal-Mart are those who would never shop there and don’t know anyone who does shop there.

It’s always nice to find evidence to back my inclinations. It turns out that Wal-Mart not only lowers prices for poor people, but improves their health. Reporting on this improbable result is Radley Balko, formerly at Cato and now at Reason:

In the popular imagination, a big-box store such as Wal-Mart is more often seen as part of the problem than part of the solution: We associate Wal-Mart with large women in stretch pants, fat kids sucking down tubs of soda, and morbidly obese men inching down the snack-food aisle in motorized shopping carts. The store makes candy, chips, and soda ridiculously cheap—so wouldn’t Wal-Mart contribute to the obesity problem?

That’s what economists Art Carden of Rhodes College and Charles Courtemanche of the University of North Carolina at Greensboro suspected. So they conducted a study to find out. Carden and Courtemanche have done a number of studies on Wal-Mart. Carden insists they get no funding from the company, directly or indirectly. Rather, he says, the two free-market economists have been intrigued by the Wal-Mart debate and wanted to test some of the more common criticisms of the store. Generally, they’ve found that the worst fears about Wal-Mart are unfounded, and that the stores have a mostly positive impact on their communities.

But they thought this one might be different. “We expected the study to show an increase in obesity in communities with a Wal-Mart,” Carden says. “We know that Wal-Mart lowers the cost of food, but we figured it’s not always the best food for you.”

To their surprise, they found the opposite—there was a small but statistically significant reduction in obesity rates in communities with a Wal-Mart, perhaps because the store also sells fresh produce of good quality at a good price.

Broadening the study to big-box stores in general, the effect was even more pronounced. “People actually bought more produce, more fruits and vegetables,” Carden says. “Instead of just eating more, they ate a higher-quality diet—a lower-fat diet than the rest of the population.”

It appears that people aren’t as stupid as paternalistic politicians believe. And markets ain’t half bad either.