Airbnb co-founder Nathan Blecharczyk dodged questions after making a $1 million donation to Boston Latin Academy on Monday at a time when his industry is facing strict regulations in the city that could affect his company’s bottom line.

Local government watchdog David Tureck, executive director of the Beacon Hill Institute and professor of economics at Suffolk University, called the timing of the donation “suspicious at a minimum.”

Airbnb has pledged to remove any of the 6,100 short-term rental listings from its site that don’t include a city registration by Dec. 1 and early signs suggest there could be a dramatic drop-off in the number of rooms available in a little over a month.

The city has received only 1,094 applications. Of those, 495 were approved and 465 rejected, with 134 still pending, according to Lisa Timberlake, a spokeswoman for Boston’s Inspectional Services Department.

“It seems to me that the donation was motivated as a defense against the regulations — that’s really the only conclusion you can reach,” Tureck said. “Maybe it was innocent but it seems unlikely.”

Regulations on the short-term rental industry took effect on Jan. 1 and last month the city started cracking down on illegal listings on apps like Airbnb.

The city’s short-term rental ordinance, passed in June 2018, bars so-called investor units — with nonresident landlords — from placing their properties on the Airbnb-style apps. Property owners can still rent out single rooms in their own homes, or entire apartments in two- or three-unit buildings in which they live.

Apps like Airbnb are “stealing thousands of apartments all over the city,” said Richard Giordano, policy and planning director at Fenway Community Development Corporation — something he said drives up the cost of living for residents. He said he worries that property owners will skirt regulations by seeking alternative classifications from the Zoning Board of Appeals as “boutique hotels” or “executive suites” — something city records show is increasingly happening.

“They’re not going to be hotels,” Mayor Martin Walsh said on Monday.

Walsh said that reclassification may be possible in a few cases, but not in all and said the city has a process in place to address these requests.

“We have such a shortage of homes especially the kinds of (affordable) homes that we need and when homes are taken off the market, it puts us deeper in trouble of meeting the housing needs of everybody,” said Rachel Heller executive director of the Citizens’ Housing And Planning Association.

Federal Housing Finance Agency director Mark Calabria said Boston’s short-term regulations could have consequences for the housing market.

“How will short-term rentals play out in a stressed market? We don’t know,” he said.

Calabria said large numbers of investor-owned properties — like the ones Boston’s regulations are trying to eradicate — could be a warning sign that a downturn in the housing market could be coming. The number of investors in the housing market has reached “pre-crisis” levels and is one of several “red flags” to regulatory agencies that the markets could start to slow.