Why density is declining in US metro areas
Most new housing development in the United States has occurred in low-density areas since the 1940s, a new study states. Building in these areas may be easier for a number of reasons, but it has also led to increased sprawl since the 1950s.

As noted by Richard Florida in The Atlantic City Lab,new study by the urban economist Issi Romem of BuildZoom sheds light on both America’s historical pattern of growth and development as well as how these patterns shape the trade-offs and choices we have about our future. Using detailed data from the American Community Survey, Romem tracks the connection between housing development, sprawl and density since the 1940s.

In his previous research, Romem made a basic distinction between so-called “expansive” and “expensive” cities or metro areas. “Expansive cities” as their name implies, have sprawled outwardly and in doing so remained largely affordable. “Expensive cities” are more hemmed in by geography and have not been able to expand nearly as much, and have seen their housing prices increase as a result. The developed footprints of “expansive” Las Vegas and Atlanta, for example, have expanded by more than 200 percent between 1980 and 2010, compared to just 30 percent for expensive New York and San Francisco.

The general trend toward sprawl turns on the simple fact that it is far cheaper and far easier to add new housing at the periphery of metros than it is to build in already built-up areas. Undeveloped areas have by definition little or nothing on them. They are essentially virgin territory, so there is much less regulation of or opposition to new development. It is harder to assemble property in already built-up areas and such development faces greater land-use restrictions and more resistance from existing residents. 

While most urbanists—including Romem—think sprawl is bad, it does offer communities a way to deliver both affordable housing and preserve their urban neighborhoods. The downside here, of course, is increased congestion and environmental degradation. Alternatively, metros that choose to limit sprawl and densify can make housing more affordable, but that can also come at the expense of character and “charm” of their existing urban neighborhoods. For metros that do nothing—that neither sprawl nor densify—housing prices will go through the roof. Existing homeowners and the rich gain, while the poor and working classes are priced out.

See the full story in The Atlantic City Lab