'What We Haven't Figured Out Is the Question of Gentrification'

Maintaining enough affordable housing and keeping income diversity in a city as it prospers are two of the most contentious and perplexing questions in U.S. urban policy today. In a CityLab panel on urban expansion, economist and New York University professor Paul Romer decried rent control and argued that affordability is a problem for the free market to solve — and met with objections from Amanda Burden, director of New York City’s department of city planning.

"I had believed that if we kept building in that manner and increasing our housing supply … that prices would go down," Burden said. "We had every year almost 30,000 permits for housing, and we built a tremendous amount of housing, including affordable housing, either through incentives or through government funds. And the price of housing didn’t go down at all. That’s a practitioner’s point of view."