The MDRI - Mortgage Default Risk Index - is a unique search query-based index of mortgage default risk in key U.S. housing markets. Using extensive real-time and broad-based data from Google, the MDRI compiles information from Internet search query for terms such as "foreclosure help" and "government mortgage assistance" to formulate the index. The MDRI uses a much larger number of observations than traditional indexes and accordingly can be estimated for many metropolitan areas and at high frequencies. The ability of the MDRI to predict such outcomes as housing returns, mortgage delinquencies, and subprime credit default swaps has been demonstrated in peer-reviewed academic research (see, "Mortgage Default Risk: New Evidence from Internet Search Queries", Journal of Urban Economics, Volume 96, November 2016, Pages 91-111).
The MDRI is updated regularly and published by the UCLA Ziman Center for Real Estate in the UCLA Anderson School of Management. It was developed by Professors Marcelle Chauvet, Stuart Gabriel, and Chandler Lutz.
At the peak of the business cycle in December 2007, the MDRI identified San Diego, Las Vegas, Los Angeles, and Phoenix as the cities most at-risk of experiencing widespread mortgage defaults. Below is a table that ranks the 20 Case-Shiller by growth in their Mortgage Default Risk Index (MDRI) from January 2006 to December 2007: