A couple stand among tulips in front of a house
Ryan Blotnick and Keri Kimura gather fresh flowers for the rooms of their Southwest Harbor home to prepare for incoming Airbnbers in 2016. Credit: Micky Bedell / BDN

More Mainers across the state have begun to rent their homes out to vacationers on Airbnb and other short-term rental sites. But many have questioned whether their decisions could be contributing to more expensive housing for everybody else.

More than half a million guests stayed at an Airbnb in Maine in 2019, the latest year available, generating $91 million for hosts, according company data. It is difficult to determine an identical effect of Airbnb units across all neighborhoods and communities, but studies over the past few years show a clear trend of decreasing the supply of long-term rentals and likely raising costs of renting and buying.

Maine faces a housing crisis that has made many communities unaffordable for middle-class residents and the increased popularity of Airbnbs could pose a problem for buyers and renters, especially in tourist communities including Portland and Bar Harbor, which have begun to regulate them. But restaurants, bars and shops rely on vacationers being able to easily stay in Maine and communities who regulate the market too much lose out on business.

Though people stay in short-term rentals across Maine, many of Airbnb’s top spots are clustered along Maine’s coast. The county with the highest rate of stays in 2019 per capita was Hancock County, where the 82,700 guests far exceeded the county’s population of 55,000 in 2020. The company no longer releases data by community, a spokesperson said.

It appears likely that landlords renting out to Airbnb users rather than long-term renters is decreasing the number of available long-term rental units, but the problem is complex. Research released last month by Harvard University’s Joint Center for Housing Studies found that while Airbnb likely led to higher rents in New York City, most of the financial burden fell on high-income renters.

A 2021 study by Carnegie Mellon University researchers found that communities with more Airbnb units tended to decrease long-term rental supply because landlords switched units to Airbnbs to the detriment of affordable housing. They also found the presence of Airbnbs expanded the overall renting housing market to the likely benefit of lower-income landlords.

Other research is more unequivocal about a negative effect on the housing market. Another study found that rent and home values each dropped 3 percent in communities where cities prohibited Airbnb operators from renting out more than a single address at a time.

Some Maine communities have taken similar actions. Kittery began tracking and regulating the units in 2020, setting a cap on properties in town and requiring landlords to register their units with the town every year for a fee.

Those who didn’t register face a $250 fine and the town can deny permits to properties that break the law or violate city ordinances. The moves came after an “explosion” of new Airbnb properties in town, Town Council Chair Judy Spiller said.

“Our concern was that properties were being taken up that could have been used for affordable housing,” Spiller said.

The ordinance had succeeded in its goal of decreasing the number of Airbnbs in town, especially in the most densely populated part of Kittery, she said.

Short-term rentals are not going anywhere, said Matt Lewis, president of HospitalityMaine, a group that represents hotels and restaurants. But municipalities in Maine should be able to regulate the number of these listings.

“We would support the option of booking with short-term rentals provided restrictions in cities apply and can limit the impact to traditional hotels, inns,” Lewis said.

Asked about the effect of short-term rentals on Maine’s housing market, MaineHousing Director Daniel Brennan said he was hopeful that development of accessory dwelling units, a secondary residence on an existing property where people often house Airbnb renters, can increase the amount of affordable housing in Maine.

Another study published in the journal “Marketing Science” in 2021 found that Airbnbs were most likely to increase rents and sale prices in neighborhoods with low rates of owner-occupancy housing. It also found that they decreased the supply of long-term housing units.

Airbnb officials have largely denied that the company plays an integral role in the rising costs of the housing market, noting to The New York Times that many property owners rent out units to make ends meet.

“It is unfair to cynically single out our Host community and blame them for what is ultimately a complex public policy issue,” the company responded to a proposal to regulate units in Hobart, Australia.