Study: 1% increase in "detached" housing correlated with 10.8% increase in price decline

UntitledFrom CNU-sponsored researcher Kevin Gillen: "This report analyzes how varying levels of house price declines are correlated with varying characteristics of New Urbanist principles: walkability, central location, density, mixture of uses and access to public transportation. "In Philadelphia, during the most recent housing downturn of 2007-2012, home price declines have been greatest in the relatively low-density suburbs (-32.7%), second-most in Philadelphia county (-26.7%) and the smallest in the urban core of Center City (-20.2%).

"The R-squared indicates that 76% (out of a possible 100%) of the regional variation in house price declines are explained by the location, design and socio-economic characteristics of the individual communities.

  • Every 1-person increase in a Zip’s population density is associated with a - 0.00287% decrease in the magnitude of house price declines.
  • Every 1% increase in the percent of a Zip’s building stock that is classified as 'residential' is associated with a 70.4% increase in the magnitude of house price declines.
  • Every 1% increase in the percent of a Zip’s housing stock that is classified as 'detached' (as opposed to “attached”) is associated with a 10.8% increase in the magnitude of house price declines.
  • Being a Zip code that contains a balanced mix of both residential and commercial properties is associated with a 6.4% decrease in the magnitude of house price declines.
  • Every additional business (per square mile) that a Zip code has is associated with a 0.01% decrease in the magnitude of house price declines."

"Homes in mixed-use, walkable, relatively higher-density neighborhoods and communities with access to public transportation retained relatively more of their value during the bust.  They were worth an average of $192,624 by the time the market hit its bottom in 2012.  [See chart above.]  By contrast, the dwellings that lost the most of their value were in areas that had a high degree of residential-only development and a high percentage of detached homes. Their average post-bubble value was $111,329."  Full paper here.