A map of the raw data reveals that St. Louis County’s recent single-family home

foreclosures have been concentrated in the northern part of the county.

To locate statistically significant foreclosure hot spots, the raw foreclosure counts

were normalized by the number of single-family parcels to yield a foreclosure rate for

each Census block. Parcel and foreclosure data came from the county’s GIS Service

Center; block data came from the U.S. Census Bureau.

First, the parcel data was prepared using the following ModelBuilder program:

Then, the foreclosure data was joined to the parcel and block data, as follows:

Hot-spot analysis of St. Louis County, MO single-family home foreclosures, 2007-2011

Nancy Cole, GIS Certificate Student

University College, Washington University in St. Louis

Background The United States is currently in the throes of the deepest recession since the Great

Depression of the 1930s. Home foreclosures, driven by sub-prime lending and

adjustable-rate mortgages, have been an important factor in this recession.

St. Louis County has not escaped the

rising tide of foreclosures. Between 2007

and 2011, the number of single-family

home foreclosures were roughly double

the number for the previous five years.

The county covers 524 square miles, has 371,689 land parcels – 318,937 of them

classified as single-family, and – as of 2010 – 18,747 Census blocks and 199

Results

Conclusions

References 2012 State of the County, St. Louis County, MO, PowerPoint presentation, 2012 Strategic

Plan Kick-off.

Delgadillo, Lucy and Luke Erickson, “Spatial Analysis of Residential Mortgage

Default in a Metropolitan County,” Housing and Society, 2006, 33:1, 40-48.

Malkova, Olga, “Determinants of Foreclosure: A Chicago Case Study,” Senior Honors

Thesis, Economics Department, University of California, Berkeley, 2008.

Rogers, William H. and William Winter, “The Impact of Foreclosures on Neighboring

Housing Sales,” Journal of Real Estate Research, 2009, 31:4, 455-479.

Research Questions

Acknowledgements & Contact Information

Thanks to Bill Winston, Melisa McLean,

Adam Roberts, and Todd Swanstrom.

nancycole01@gmail.com

December 18, 2012

1. Where have recent single-family home foreclosures occurred?

2. Does St. Louis County have statistically significant foreclosure “hot spots”?

3. Are foreclosures correlated with household income, share of college graduates,

percentage African-American residence, or the racial “diversity index”?

Data & Methodology

2009 “Central Feature”

Data & Methodology (continued) Next, the raw foreclosure data was normalized by the number of single-family parcels

to yield a foreclosure rate, as follows:

Finally, the Getis-Ord Gi* tool was run using a Spatial Weights Matrix file, which

simplifies re-analysis using different assumptions:

According to Rogers and Winter, economists at the University of Missouri at St.

Louis, real-estate researchers commonly use a “K Nearest Neighbors” weighting

structure. Rogers and Winter used 10 nearest neighbors in their own analysis of

residential foreclosures in St. Louis County.

Statistically significant hot spots are concentrated in northern St. Louis County.

When compared with choropleth maps of various socioeconomic indicators by

Census tract, the hot spots are positively correlated with the percent of population

African-American and, to a lesser degree, negatively correlated with median

household income. Correlations with the percent of population holding four-year

college degrees and with USA Today’s diversity index are less evident.

Census tracts.

From 2007 through 2011,

20,465 properties were

foreclosed on; 18,699 of

them were single-family

homes.