Nobel Prize-winning economist Robert Shiller warns that the coronavirus pandemic could cause a decline in urban housing prices if employees continue to work from home and skip city life.

“I think there’s a risk that home prices in urban areas may decline,” Shiller told CNBC.

The U.S. housing market surprised economists by rallying in the midst of a pandemic.

The Yale University professor explained that the benefits of city living, such as restaurants, museums or theater shows, have been put into question during the coronavirus pandemic.

“People forget that a lot of the value of homes outside of the central city is in the structure and you can build more of them,” he said. “Home prices out of the dense urban setting tend to follow construction costs, and so there shouldn’t be any big movement in those prices,” said Shiller, who helped develop the widely-followed S&P/Case-Shiller Home Price Indices.

Shiller also said assets are “highly priced” across major markets, including housing, stocks and bonds.

Meanwhile, the most recennt S&P CoreLogic Case-Shiller 20-metro-area house price index increased 4.0% from a year ago in April after rising 3.9% in March.

To be sure, a forecast by CoreLogic Inc.said housing prrices will fall about 6.6% in the year through May 2021, the first annual decline since 2012, as the economic damage from the pandemic deepens.

That’s a stark shift from the path the market has been on recently, as record-low mortgage rates spur purchases and tight supplies push up prices, Bloomberg explained. The momentum is unlikely to hold with persistently high unemployment that may worsen as increasing cases of the virus force some state governments to delay or scale back their reopening plans.

“By the end of summer, buying will slacken and we expect home prices will show declines in metro areas that have been especially hard hit by the recession,” CoreLogic Chief Economist Frank Nothaft said in a report laast week.