Considerations in the Design and Construction of Investment Real Estate Research Indices

This paper surveys some of the major technical issues in the design and construction of real estate research indices, both appraisal-based and transactions-based. The paper considers property sampling issues, differences between transaction prices, market values, and appraised values, the trade-off between random measurement error and temporal lag bias, optimal reporting and property revaluation frequencies, and the uses and limitations of modern statistical techniques. Although one of the conclusions of the analysis is that most research questions are best addressed with transactions-based, rather than appraisal-based, indices in the United States, the paper suggests how appraisal-based indices can still be useful for some research purposes.