The state of Maryland wants more people to have affordable housing — at least if they’ve already got it. Concerned that the owners of mobile home parks might sell the land for other uses, “affordable housing advocates” succesfully lobbied Maryland legislators this year for

legislation that, they say, discourages owners of mobile-home parks from selling their properties. If the landowner does sell, it provides the homeowner with some protection.

Under the law, which was passed earlier this year, a mobile-home park owner who wants to sell and change land use must give written notification to the residents and provide displaced homeowners with a relocation plan and relocation assistance that equals 10 months’ worth of rent. The legislation applies to mobile parks with more than 38 sites.

Now the first thing to be said about this is that it is theft. That’s become so common in legislatures that we’ve become accustomed to it. But we shouldn’t lose sight of what happened here: Some people spent their own money to buy land. They rented that land to people with mobile homes, who knew that they were not buying the land, they were just renting a place to park their mobile homes. (The word “mobile” might be a tipoff that they’re made to move.) And then the government took away the owner’s right to change the use of his land. The owner could still sell it, of course, as long as he gives written notification of his plans, provides the renters with a “relocation plan,” and pays them 10 months’ rent to leave his land. That’s a huge burden; the government has simply appropriated much of the value of the owner’s land.

But there’s an obvious long-term consequence here, too, one that the Washington Post didn’t get to in its 1000-word story. What’s going to occur to a landowner as she reads this story? She’s going to think, if I allow anyone to park a mobile home on my property, I’ll be permanently harnessed to that tenant, like a medieval serf. So maybe I’d better not rent any space to a mobile home owner. But then she’s going to think a bit further: What about other kinds of affordable housing? If I build inexpensive apartments or bungalows, and rent them to people who need affordable housing, will the state of Maryland decide that I shouldn’t be allowed to change the use of the land or sell it? After all, wealthy Montgomery County, Maryland — which doesn’t have many mobile homes — does have a 20-page handbook of rules and restrictions for any owner who might want to convert an apartment building to condominiums, including the county’s right to buy the land and a guarantee of lifetime tenancies for low-income elderly tenants. William Tucker pointed out in a 1997 Cato paper how rent control laws usually had to be followed by condo conversion restrictions, as building owners tried to find some way to make a profit on their buildings. And then of course the whole series of attempts to “protect” affordable housing leads to housing shortages and sky-high rents.

If you want people to supply affordable housing, it’s probably a good idea not to pile taxes, restrictions, and threats of confiscation on the backs of those who do.