It was quite a straddle for Mayor Bloomberg yesterday. In the afternoon, he called on the federal government to allow the city to import medicine from Canada, where prices are lower because of Canadian government regulation. “Price controls are the wrong thing to do,” Mr. Bloomberg said, according to a report today by our Dina Temple-Raston. The mayor added, according to Ms. Temple-Raston’s report, that marketplace should set prices, not governments.

We couldn’t agree more with the mayor on that point. Which is why it is so baffling that the same mayor who spent the afternoon proclaiming his opposition to price controls on medicine spent yesterday morning trying to extend additional government price controls on apartment rents in Manhattan.

“Today, our administration takes another important step in preserving middle income housing by proposing new State legislation to protect more than 32,000 Mitchell-Lama tenants from large rent increases,” Mr. Bloomberg said in a press release announcing the housing initiative. “At the same time, it is critical that we provide tax relief to owners who will now be newly rent regulated.”

The “protection” that rent stabilization offers these Mitchell-Lama tenants is akin to the “protection” that the Canadian government offers medicine buyers. It’s not real protection, it’s interference that stifles genuine development and innovation, as Mr. Bloomberg no doubt understands. If New York had a natural housing market, some tenants might be displaced, but it would be more efficient and better for the city as a whole. And in the not-so-long run, a greater supply of new housing would be built, bringing downward pressure on the price of rents.

Among the apartments to be “stabilized” under Mr. Bloomberg’s plan are buildings in Gramercy Park and the West Village, which are among the city’s most expensive Manhattan neighborhoods. If the lucky few living at below-market rents there were forced to move, maybe they’d help improve neighborhoods in the outer boroughs, where market rents are more affordable. As it is, the special deals grandfather in a lucky few but leave other, less lucky New Yorkers chasing fewer units of housing than would otherwise be available at market rates.

We all know stories of empty-nesters who remain in three-bedroom rent-stabilized apartments at scandalously low rents rather than moving to smaller places. Why would anyone give up such a sweet deal? Meanwhile, new arrivals to the city have their children sleeping in closets and bathtubs — and end up paying more.

The best way to allocate housing units fairly is by letting people pay for what they need, without the city government creating or extending incentives to prevent people from moving. We recognize that Mr. Bloomberg is a high-integrity individual who strives to do what he thinks is right. But we don’t mind saying we hope that when Republicans in Albany take up Mr. Bloomberg’s plan to expand government price controls in the city’s housing market, they’ll refer him to the remarks he made yesterday: “Price controls are the wrong thing to do.”