經濟折舊(economic depreciation)係指資產價值隨時間經過而降低者。於不動產之建築物部分，因實質毀損而使價值呈遞減趨勢；土地部分，一般則視其不發生折舊 (Fisher et al.,2005)。折舊之相關實證研究中， Malpezzi et al.(1987)之後許多研究以屋齡及屋齡平方為自變數進行迴歸分析，兩者係數往往達顯著性水準，顯示不動產價值在建築物耐用年數期間價值先降後昇，使不動產價值遞減的折舊觀點受到質疑。本計畫擬建立不動產包含土地再開發實質選擇權之價值理論，以釐清土地之再開發價值，並作為實證分析之基礎；繼而以高雄市房地產交易價格資料進行複迴歸分析，分別推估透天住宅土地、建物及不動產的折舊情形，以說明不動產價值逆折舊現象，導因於土地使用價值與再開發價值的交互作用，致呈現先降後昇之情形。此外，藉由不同地區、不同景氣階段的理論推演與實證結果，進一步驗證逆折舊分析之合理性。本研究繼梁仁旭與陳奉瑤(2009)分析之後，除建立理論基礎外，並改間接為直接驗證方式，且經由比較分析更加支持逆折舊之論述。
Economic depreciation is the decline in the value of an asset over time. Building value decreases because of physical deterioration, but the depreciation does not occur in land value (Fisher et al.,2005). Many references after Malpezzi et al.(1987) adopt age and age-squared to be variables and the outcome is always significant. It shows that real property value decrease firstly and do increase in its residual economic life. So the issue of “real property value always decline” is doubted. By drafting and establishing the real estate value using land redevelopment real option, we can clarify the worth of land redevelopment, and use it as the base of empirical analysis. We use real property price database from Kaohsiung City and adopt multi-regression analysis to discuss the depreciation pattern of land, building and real property. The result will show reversion of real property depreciation due to the interaction of land’s use value and redevelopment value. Furthermore, we will analysis different area and different stages of business cycle to prove the rationality of depreciation reversion.
