Comparing the Accuracy of the Minimum-Variance Grid Method to Multiple Regression in Appraised Value Estimates

The adjustment-grid method and the multiple-regression method are the two most frequently used techniques in the sales comparison approach. This paper demonstrates that although both techniques provide unbiased estimators, the minimum-variance grid estimator should result in a smaller standard deviation than the multiple-regression estimator. A technique is also derived to estimate the confidence interval or to perform hypothesis tests for the minimum-variance grid estimator.