Data include first-lien mortgages on 1-4 unit residential properties as of March 1, 2011. To approximate the full universe of residential mortgages, data are aggregated from two sources depending on mortgage type. The source of privately securitized mortgage data is CoreLogic LoanPerformance (LP); the source of data on all other mortgages is Lender Processing Services Mortgage Performance data (LPS).
These data do not represent the total number of residential mortgages in each geography but the unadjusted loan counts from the source databases. As of 3/1/2011, the data sets provided monthly loan-level information on approximately 34.9 million active loans in the United States, estimated at 65 percent of the total number of mortgages. However, coverage varies by category and geography.
The House Price Indexes at the county and zip code level are from CoreLogic LoanPerformance (LP). To mitigate small-sample concerns, we use a three-month moving average of the HPI that includes all sales in the zip code, including distressed sales.
Housing Unit data are owner-occupied data from the Census American Community Survey, 2005-2009 estimates.