台灣地價稅資本化探討－－縣市合併的準實驗

LAND VALUE TAX CAPITALIZATION IN TAIWAN: A QUASI-EXPERIMENT OF CITY-COUNTY MERGER WITH ADMINISTRATIVE TAX DATA

本文使用財政部財政資訊中心2007–2015年全國土地財產檔，以2010年底台中、台南與高雄縣市合併升格後，2013年重新規定累進起點地價作為準實驗（quasi-experiment），採差異中的差異法（difference-in-differences，DID）分析我國地價稅租稅資本化（tax capitalization）情形。實證結果發現，原台中縣與苗栗縣、南投縣和彰化縣交界區及原高雄縣與屏東縣交界區存在租稅資本化現象，地價稅負擔與土地價值呈現負向關係，縣市合併後土地公告現值平均提升5.81%與4.24%;進一步估計此二交界區資本化的程度，在以一般房貸利率2%的折現率下，DID估計的資本化程度約為87.6%與67.3%，而連續DID的估計則為92.9%與41.4%。相較於其他國內外文獻，不僅顯示資本化程度高，也隱含我國地價稅轉嫁予購地者的比重較低。

We use administrative tax data from 2007 to 2015 to examine the capitalization of the land value tax in Taiwan, exploiting quasi-experiments of three city-county (Taichung, Tainan, and Kaohsiung) mergers in 2010, and the associated re-assessment of the land value tax bases in 2013. Results from the difference-in-differences (DID) estimators provide robust evidence of capitalization in border districts of original Taichung and Kaohsiung counties. After the mergers, the values of county lands (as measured by the assessed present values) increased by an average of 5.81% in Taichung county and by an average of 4.24% in Kaohsiung county. Two different approaches are used to calculate the degree of capitalization. Using the general mortgage interest rate of 2% as the discount rate, the usual DID imputation suggests the degrees of capitalization of land value taxes are 87.6% and 67.3% in Taichung and Kaohsiung counties, respectively, while the continuous DID imputation suggests the corresponding degrees of capitalization are 92.9% and 41.4%, respectively. The degrees of tax capitalization we calculate are higher than the findings in most previous research, suggesting that land value tax incidence largely falls on land owners.