臺灣七大都市地區房價所得比之差異與迷思──購屋者擁屋數與主觀因素分析

Differences and Myths about House Price-to-Income Ratios in Taiwan's Seven Largest Cities: An Analysis of Buyers' House Ownership and Subjective Factors

臺灣近年來由於房價高漲，住宅負擔問題成為關注焦點。本研究以個體房價所得比視為住宅負擔，以擁屋數（資產部分替代變數）、主觀因素及臺灣七大都市地區為研究主軸，探討房價所得比之三大迷思：一、高房價低所得現象背後反映購屋資金並非單純倚靠所得，擁屋數（資產）也可能為重要來源；二、探討住宅負擔時僅探討客觀因素，卻忽略購屋者主觀因素（支出壓力或房價趨勢看法）影響力；三、高房價或高房價所得比背後代表高住宅負擔，臺北市為房價之首，住宅負擔也為全臺之首。本研究透過最小平方法及分量迴歸模型檢視七大都市地區房價所得比之差異，實證結果顯示，高低分量數值差異最大為區域別（臺北市）及購屋目的（自住或投資），缺少衡量擁屋數會使住宅負擔高估、購屋者對於房價看法或支出壓力等確實影響住宅負擔，而七大都市地區中，低房價地區（高雄市）反比高房價地區（臺北市）住宅負擔重。整體而言，資產（擁屋數）確實為重要購屋資金來源，探討購屋者主觀因素有助於分析住宅負擔，而高房價或高房價所得比背後並不代表高住宅負擔。

Against the background of soaring house prices in Taiwan, housing affordability has become a focus of concern. This study determines the housing affordability of an individual according to his or her house price-to-income ratio (PIR). The research framework was established using house ownership (i.e., the number of houses owned) as the proxy variable for assets and subjective factors, with a focus on the seven largest cities in Taiwan. Three myths about PIRs are discussed in this study: (1) A high PIR indicates that an individual's financial ability to buy a house does not solely depend on his or her income, but is instead largely contributed by his or her house ownership (assets). (2) Housing affordability is usually discussed in relation to objective factors; subjective factors from the house buyer's perspective are often excluded from the equation. (3) A high house price or high PIR means low housing affordability, with the result that the city with the highest house prices (Taipei) should exhibit the lowest housing affordability. This study used the method of ordinary least squares and a quantile regression model to explore the differences among the PIRs in the seven largest cities in Taiwan. According to the empirical results, assets (house ownership) serve as the primary source of finance for buying houses. This investigation into house buyers' subjective factors is conducive to analyzing their housing affordability, and a high house price or high PIR does not necessarily indicate low housing affordability.