不動產自動估價與估價師個別估價之比較— 以比較法之案例選取、權重調整與估值三階段差異分析A Comparison of Automated Real Estate Valuation Models and Appraisers’ Appraisals—Comparables Selection, Weighting Adjustment and Valuation for the Sales Comparison Approach
In real estate appraisal research, appraisers and mass appraisals are the two methods most often used in the sales comparison approach. In the past, most appraisers’ studies focused on the appraisers’ behavior or on improving appraising methods. Since these two methods are constructed in different ways, it is not easy to find enough objects for the analysis and a comparison between appraisers and mass appraisal. The main purpose of this paper is to select certain target cases and then compare the data provided by appraisers as well as the results of mass appraisals. The analysis is conducted in three stages: selecting comparables, adjusting weights and estimating values. The differences in the analysis indicate that the differences in the Automated Valuation Model (AVM) of the Minkowski metric of the comparables is smaller than the appraisals provided by individual appraisers. The findings indicate that the application of the AVM model is more objective and fits the appraisal procedure. However, with the limits of the AVM, the sparseness of the data and non-typical housing, the results of the AVM in some areas differ from those made by appraisers, which indicates that the AVM has limitations. This situation is expected to improve as a result of accumulating more data and adjusting the models.If the accuracy of the AVM is assured, the AVM will be applied more widely.
Key words: real estate appraisal, mass appraisal, automated valuation model, sales