理論上建議住宅價格與家庭所得應維持在一定的比值，然而過去數十年間，國內住宅價格產生相對於所得的高度循環變動現象，特別是最近一次（民國70年末期）的住宅價格劇漲使此比值突增一倍，造成這段期間內住宅負擔能力急速惡化。然而住宅價格真的會脫離所得到達大部分家庭難以負擔的程度，或者這現象是屬短暫的不均衡？而這現象到底是何種因素造成？本文首先分析住宅價格與家庭所得是存有何種均衡關係，是否持續惡化，接著分析住宅負擔能力的惡化到底是何種因素造成。研究結果發現，傳統共整合(cointegration)則試無法提出證據顯示家庭所得與住宅價格在長期存有共同的趨勢，然而我們採用Engle與Smith在1999所提出的STOPBREAK模型來檢定，卻說明了此二者雖然受到衝擊影響時會有短暫背離，但仍然存有相依變動之均衡關係，我們再對住宅價格與所得比例的則試，也發現國內住宅負擔能力的惡化是暫時的現象。而藉由向量自我迴歸模型之變異數分解分析，我們發現代表投資需求的貨幣供給量變數影響住宅價格短期之變動甚劇，可能是造成住宅價格短期偏離所得之重要原因。

Theory suggests that household income should maintain a stable ratio with house prices. However, the growth of house price is much higher than growth of income in Taiwan. The recent boom in the late 1970s of house prices cause this ratio to a higher level, resulting in housing affordability problem. Previous studies in Taiwan indicate that house prices have deviated the long-run trend in income. Is the house price really increasing faster than income, or this is only a temporary phenomena? Therefore, this paper tries to investigate whether there is an equilibrium relationship between house price and income, and what are the causes of the short-run deviation. The empirical results suggest that there is no evidence of common trend between these two series by using traditional cointegration test. However, by using the STOPBREAK model proposed by Engle and Smith (1999), we find evidence of the long-run equilibrium relationship. Further testing on the house price to income ratio also provides the support that deviation of the ratio could be temporary. And the results of variance decomposition indicate that the short-run house price fluctuation is greatly explained by money supply, suggest that the deviation between house price and income is caused by investment demand.