Home-sharing platforms like Airbnb, VRBO, and HomeAway can offer visitors to D.C. all sorts of options for cheap places to stay, but they also seem to be making parts of the city more expensive for long-term residents.

That’s the conclusion of a new research paper from a Zhenpeng Zou, a doctoral student in urban and regional planing at the University of Maryland, who looked at the impact on housing prices of Airbnb and other homesharing services in D.C. neighborhoods from 2015 to 2017.

“I found on average a 2.24 percent price inflation of single-family housing,” he says.

While Zou says that inflation is “mild” and comparable to other similar studies in cities like New York and Boston, it was more pronounced in certain neighborhoods—exceeding 5 percent in places that are already tourist hot spots like downtown D.C., Dupont Circle, Adams Morgan, and Foggy Bottom. And he says it may also have an outsized impact on some minority groups in the city.

“I also found some historically minority populated neighborhoods like Shaw, Trinidad, Capitol Hill, and Columbia Heights, where the price effect was larger, on average 3 percent. I think that is also very alarming because a lot of these neighborhoods have a high percentage of minority populations. It can really affect the ability for the first-time homebuyers to basically find a single-family property in these neighborhoods,” he says.

Home-sharing has grown in popularity in recent years—in D.C. alone there are almost 7,000 offerings on Airbnb—but has also drawn controversy. Beyond fights over parking and out-of-control parties at rented properties, critics say it hurts long-term renters and prospective purchasers by taking homes off of the market altogether and thus making what housing remains more expensive.

That argument has been central to efforts in cities nationwide, D.C. included, to rein in home-sharing services, largely under the guise of protecting affordable housing options in places that have fewer and fewer of them.

Airbnb has long denied it is causing home prices and rents to go up and says that other factors like restrictive zoning are more likely to be responsible for price spikes. And the San Francisco-based company says that it offers residents a chance to monetize unused space in their homes—something that may actually allow them to remain in high-priced cities like D.C.

“Over the past few years, our host community across the District—and especially east of the Anacostia—have shared how they depend on the extra income from sharing their home in order to keep their home, whether they are looking to buy their first home or to just afford to stay in the home their family has lived in for generations. The reality is that short-term rentals are a financial tool for many D.C. residents,” said an Airbnb spokesperson in an emailed statement.

Airbnb says that from June 2017 to May 2018, residents in Wards 7 and 8 hosted more than 29,000 guests and earned $3.75 million in extra income, and that those guests spent $94 million at businesses across the city throughout 2018.

Zhou, 29, says his study didn’t determine whether home-sharing leads to higher rents, though he posits that the higher sales prices of single-family homes noted in his research “will eventually be borne by long-term renters, jeopardizing low-income minority renters.” (One study found that to be the case in Boston, and another in Barcelona.) He also didn’t reach any broader conclusions on the impacts of home-sharing on gentrification in D.C. But he says the study does suggest that balanced regulation on home-sharing is needed.

“I believe there also needs to be a balance between regulations that are effective to take away the incentives to overheat the housing market. But on the other hand, we don’t want it to be too restrictive in the sense that people can no longer rent out their primary dwelling,” he says. “In general, I feel like the sharing economy has a lot of potential to solve some of the housing market crisis, but there has to be a lot of enforcement and regulation to take out the incentives to commercialize the market.”

In D.C., a new law limits home-sharing to a homeowner’s primary residence and imposes a 90-day annual time limit when they are not present during the rental. (There are exceptions for homeowners who travel extensively for work.) Airbnb has called the law “stringent” and “onerous;” while it is on par with similar laws in New York and San Francisco, it’s among the most restrictive in the region.

But while D.C.’s law has been on the books since last October, it isn’t yet being enforced. The city still has to issue regulations detailing how hosts and home-sharing services can come into compliance, and officials say once those rules are published they will give everyone three months to get on the right side of the new law.

This story originally appeared on WAMU.