從房地價格分離探討地價指數之建立

Establishing Land Price Index by Detracting from the Real Estate Price

由於區段地價為土地稅及內政部都市地價指數的主要參考資料，因此，政府依據地價調查所得的地價資料，關係著政府課徵土地稅的公平性及都市地價指數的準確性，故其正確性及合理性與否是相當重要的。本文實證結果發現，在控制相同自變數的地價模型，聯合貢獻說分離地價資料所建立地價模型於各項比較結果均較佳，可知以聯合貢獻說分離房地價格較為合理，此外，土地貢獻說分離地價平均高於聯合貢獻說分離地價13.13%，若以土地貢獻分的離方式建立地價指數，其地價指數波動較大。本文與內政部地價指數比較，發現地價調查估計規則的房地分離方法，在建物價格估算上多考量裝潢費用，造成高估房地的建物價格，且造成地價模型配適亦不如聯合貢獻模型，其分離地價平均低於以聯合貢獻說分離地價7.98%。在地價指數方面，亦因低估地價造成內政部地價指數平緩的現象，並發現以控制土地品質地價指數的趨勢較接近房價指數，且較能確實反映市場情形，為內政部地價指數編製方法的不足之處，主要是因內政部未控制選樣品質造成指數趨勢變動偏離所致。 Real estate valuation theory indicates three principles of contributions: land contribution, building contribution, and joint contribution. Many researchers advocate the principle of land contribution because land is sustainable and without depreciation. According to valuation and economic theory, the principle of joint contribution conforms to the theoretic implication comparatively; therefore, it is worth exploring the debates between the principle of land contribution and the principle of joint contribution. Compared to the land price index of Ministry of the Interior, this paper tries to find a more reasonable allocation ratio and establish a land price index. Empirical evidences seem to indicate that the land price model based on the principle of joint contribution is better than is the model based on other principles. On the contrary, the trend of the land price index of the Ministry of the Interior is different from the housing price index because land quality is not controlled.