The basis of the S&P/Case-Shiller Home Price Indices (S&P/CSIs) is the pioneering research of economists Karl Case and Robert Shiller, who, beginning in the 1980's, collaborated and later co-founded Case-Shiller Weiss, Inc. ("CSW") with Allan Weiss in 1991. In May 2002, CSW was purchased by Fiserv, Inc. (NASDAQ: FISV) and is part of the Fiserv lender technology and services vertical.

CSW was created to offer products and services based on its economist founders home price research. The firm built upon those research efforts in the areas of data collection, filtering, analysis, and modeling and amassed a large national database of residential real estate information. CSW's extensive database has been combined with proprietary software to produce the REdex Library™, a suite of U.S. residential real estate indexes and related metrics that includes The Case-Shiller^® Indexes ("CSIs"), and CASA^®, a market-leading automated property valuation service. The Fiserv / CSW organization continuously analyzes and quality-controls residential property data collected from several sources, and uses proprietary software to produce the CSIs for real estate markets throughout the United States.

For many years, mortgage lenders, securities issuers, insurers and rating agencies have utilized the CSIs to accurately track U.S. residential real estate trends and manage home price risk. The CSIs are widely recognized as the most authoritative and trustworthy home price change measures for market and loan portfolio surveillance, customer retention, loss reserve reviews, mortgage default, loss and prepayment analyses.

The CSIs were originally developed so that economists, financial institutions, rating agencies and others could study with precision the causes and consequences of home price changes on the U.S. economy. Until their development, the most widely used information on home price changes were indices based on the change of an area's median home prices. Economists were frustrated with this approach, because indices based on median home prices in a particular geographic area can provide misleading indications of price changes as a result of shifts in the sampling of homes that comprise median measures from one month to another. Case and Shiller, building upon research pioneered by economists Martin J. Bailey, Richard F. Muth and Hugh O. Nourse, solved this problem by creating a repeat sales analysis in which only homes that sold at least twice over a period were covered and included in the index, thus creating an "apples to apples" analysis.