不同估價方法之權重分析與模式建立－－地價基準地之探討

Analysis and Modeling Building of the Weights from Different Real Estate Appraisal Approach: Empirical Evidence from Land Value Benchmark

不動產估價一般須兼採三種以上方法，因不同方法估值不同，需求取不同估值之關聯，協調其差異以決定最終估值。為了瞭解比較估值、收益估值與土地開發分析估值之關聯，本文將三種估價方式權重建立聯立模型，以3SLS進行估計。實證模型系統加權解釋力達95%以上，顯示三種方式間之權重配適度良好，且三種方式權重之自變數多符合預期並顯著，顯見三種方式之關聯性。隨機抽取90%推估樣本外10%之權重結果，三種方式權重之MAPE介於4%至11%之間，於20%範圍內之Hit-Rate介於87%至96%之間，顯示良好之預測成效，且以比較方式最佳。各種方法估價過程考慮因子所產生之迴歸係數，可作為估價人員應用加權平均方式協調估值結論之參考，使估價更客觀及科學化。 Real estate appraisal generally requires three approaches to value. Since the value indication of different real estate approach differs, reconciliation should be made and correlated into a value conclusion. In order to realize the weights correlation among the sales comparison value, income capitalization value and land development analysis value, this paper build a model based on the three-stage least squares method simultaneous equation (3SLS). The empirical results shows system weighted R2 exceeds 95%, which means the model fit is good and how the weights of three methods correlate. The signs of most exogenous variables on the weights of three indication of value meet expectation and are significant. After forecasting 10% validation samples modeled by 90% samples randomly surveyed, the MAPE of weights of three methods is from 4% to 11%, while the Hit rate is from 87% to 96%. The sales comparison method presents the best forecasting outcome. The regression coefficients estimated from factors during the procedure of each approach could serve for reference if weighted average is applied reconciling the value conclusion by valuers and could make appraisal more objective and scientific.