The 1992 GSE Act required HUD to create a data base on mortgage purchases by the GSEs and make it available to the public. In 1992, Congress felt there was an "information vacuum" on the type of mortgages the GSEs were purchasing. Because Fannie Mae and Freddie Mac receive significant benefits from their government-sponsored status, Congress wanted to assure that the public was getting enough in return.
Beginning with 1993, the GSEs have provided HUD annually with loan-level data on each mortgage they acquire. For the GSEs' 1993-1995 submissions, HUD copied the loan-level records to data files but omitted certain variables that had been deemed proprietary by the Secretary of HUD and recategorized the values of other proprietary variables into ranges so that they were no longer proprietary. The October 4, 2004 Final Order that established which variables were proprietary is available in text format and *.pdf format.
The single-family data sets include detailed data on the income, race and gender of the borrower as well as the census tract location, loan-to-value (LTV) ratios and affordability. The multifamily data sets include information on number, type and affordability of units and the size of the property, mortgage balance, and type of organization that sold the mortgage to the GSE.
The GSE Public Use Data Base data files that are available for 1993-95 contain information on 10.8 million single-family units and 750,000 multifamily units. The 1996 loan-level data, expected to be available by the end of the 1997 summer, would add another 3 million single-family units and 372,000 multifamily units.
The single-family component of the data base consists of three files, one of which includes census tract identifiers. The Census Tract File has loan-level information on the census tract location of the properties that secure mortgages purchased by the GSEs. This file allows analysis of areas by groups interested in local communities and smaller geographic areas. Since the Census Tract File contains loan-level records on all single-family mortgages, covering both owner-occupied and investment properties and meets the statutory requirement that HUD release the census tract location and race, gender, and income of the borrower(s), community groups and associations can analyze the borrower's characteristics as well as neighborhood characteristics of where the GSEs are and are not purchasing mortgages. This file also gives the unpaid principal balance of the mortgage and whether the mortgage was purchased by a first-time homebuyer or by a repeat-buyer.
To further fill the "information vacuum," yet protect the proprietary interests of the GSEs, HUD created additional file structures for the dissemination of important mortgage data such as the LTV, seasoned product, and purpose of the loan -- whether a purchase or refinanced loan. To accomplish this, two additional files were released that removed geographic information and added several additional variables either on owner-occupied one-unit mortgages as in National File A or, in the case of National File B, on all single-family units financed by the GSEs. However, both files still have information characterizing the location of the mortgaged properties such as the affordability of the area and the minority concentration of the census tract. For example, using National File A, an analyst could determine whether the GSEs are purchasing most of their high LTV single-family owner-occupied mortgages from predominantly white, middle class neighborhoods or from minority, lower-income neighborhoods.
The multifamily data base includes one file that releases the census tract location of the GSEs' multifamily purchases and a second file that releases information on the units in the properties financed by the mortgages. The primary purpose of the Census Tract File is to release information on the location of the property, general size of the property, and type of institution selling the property to the GSE. Whereas the National File was designed to provide information on the size of the property in terms of units and the affordability of the units in each property.