Editor: David Reiss
Brooklyn Law School

January 13, 2014

Social Security Numbers for Mortgages

By David Reiss

McCormick and Calahan have posted Common Ground: The Need for a Universal Mortgage Loan Identifier, a Department of the Treasury Office Financial Research Working Paper (#0012). They argue that

The U.S. mortgage finance system is a critical part of our nation’s financial system, representing 70 percent of U.S. household liabilities. It is also highly complex, with many finance channels, participants, and regulators. The data produced by this system reflect that complexity; unfortunately, no single identifier exists to link the major loan‐level mortgage datasets. The establishment of a single, cradle‐to‐grave, universal mortgage identifier that cannot be linked to individuals using publicly‐available data would significantly benefit regulators and researchers by enabling better integration of the fragmented data produced by the U.S. mortgage finance system. Such an identifier could additionally serve as the foundation of a system that could benefit private market participants, as long as such a system protected individual privacy. (1)

This is a very important initiative, although the privacy concerns are very important to address. Regulators have been many steps behind the private sector in tracking developments in the mortgage markets and a cradle-to-grave identifier, like a Social Security Number for an individual, will help them (and private sector analysts for that matter) to track patterns among  borrowers and loan products.

The authors identify a number of serious privacy concerns:

a mortgage identifier would have to be designed to prevent market participants from re‐identifying individuals. No links from public documents to mortgage identifiers should be allowed. Otherwise the identifier could be used to identify individuals, rendering all datasets containing the identifier personally‐identifiable information. Such a designation would create concerns about the use of individual data in the private sector and trigger burdensome requirements for government researchers using the data. (3)

Researchers have proven resourceful at mashing up data sets to identify supposedly anonymous individuals, so the privacy protections that are ultimately implemented would need to be airtight. That being said, there is a lot of value in working toward the goal of a universal identifier.

| Permalink