An Empirical Investigation of Four Market-Derived Adjustment Methods

Abstract

This study uses published data on 422 market sales of FHA/VA insured/guaranteed houses to examine and compare four methods of estimating market-derived adjustment values to be employed in the sales comparison appraisal approach. These four adjustment methods are variations and combinations of matched pair and multiple regression analysis. Two major conclusions drawn from the results are: (1) regression on matched pair data set is equivalent to matched pair analysis using regression coefficients as secondary adjustments and produces the same primary adjustment estimate for the feature of interest, and (2) even under relatively ideal circumstances, market-derived adjustments contain a high degree of uncertainty.