On April 2, Smart Growth America released a new report, Measuring Sprawl 2014, assessing development patterns across Metropolitan Statistical Areas (MSAs) and counties in the United States. Using data from the American Community Survey and other resources, the report uses a Sprawl Index tool to compare communities across four factors: residential and employment density, mix of development uses, strength of downtowns, and accessibility of the street network. Areas with a Sprawl Index score of over 100 are more compact; areas with a score of below 100 have more sprawl. Areas with a high Sprawl Index score also have greater socioeconomic mobility.
In order to measure the link between sprawl and economic mobility, the researchers used data from the Equality of Opportunity index developed in 2014. The researchers found a direct relationship between compact development and economic mobility. For every 10% increase in a community’s Sprawl Index score, there is a 4.1% increase in the probability that a child born to a family in the bottom quintile would reach the top quintile by age 30.
The researchers also examined housing and transportation costs across metropolitan areas, and found that compact communities tended to have higher housing costs. However, as the Sprawl Index score increases, the combined housing and transportation costs decline. For example, the average household in San Francisco, with an index score of 194.3, was found to spend 46.7% of its budget on housing and transportation, while a household in Tampa (FL), with an index score of 98.5, spent 56.1% of its budget on these expenditures.
The report provides policy recommendations for reducing sprawl across the United States. These recommendations include amending zoning codes to encourage mixed use development, encouraging reinvestment in existing housing stock near downtowns, and allowing higher density alongside an expedited development approval process in exchange for affordable housing.
The study, Measuring Sprawl 2014, is available on Smart Growth America’s webpage at: http://www.smartgrowthamerica.org/measuring-sprawl
The Equality of Opportunity Index can be found: http://www.equality-of-opportunity.org/