2016 年 3 月 24 日臺灣中央銀行宣布除了高價住宅的購屋貸款限制之外,將刪除台北市與新北市特定 15 個行政區的購屋貸款規範—最高貸款成數 6 成,還有自然人第 3 戶以上購屋貸款規範也一併刪除。為了探討央行此政策對於雙北特定地區房價之影響,本文使用差異中的差異法 (difference in differences),以受到政策影響之雙北特定地區房屋以及未放寬房貸限制之雙北特定地區之高價住宅分別做為本文之實驗組以及對照組,利用了 2016 年 3 月前後四年的房屋做為資料來源,針對雙北特定地區的房價做分析。發現政策在 3 個月到 6 個月之間以及 9 個月到 12 個月之間有短期影響。但是實驗組與對照組不符合平行假設,猜測一部份原因可能來自 2016 年 1 月 1 日上路的房地合一稅也影響到雙北特定地區房價,所以後續也利用三重差分法 (difference in difference in differences) 來更進一步進行研究,研究結果發現放寬房貸成數政策並不會對雙北特定地區房價帶來顯著影響,政策的實施可能成效不彰。
On March 24, 2016, the Central Bank of Taiwan announced that in addition to the restrictions on home purchase loans for high-priced housing, it also repealed the housing loan regulations for Taipei City and 15 specific administrative districts in New Taipei City, which restricted the maximum loan-to-value ratio of 60%. Moreover, the mortgage specification on natural person with more than two properties was repealed as well. In order to explore the impact of this policy, the article applies the difference in differences (DID) method to analyze the housing price in Taipei City and 15 specific administrative districts in New Taipei City by considering the affected houses in the area as the treatment group and the not affected high-priced houses in the area as the control group. The houses in the four years before and after March 2016 were used as the data source to analyze the housing prices in specific areas in Taipei and New Taipei City. The empirical result shows that the policy had a short term effect on the target housing price, more specifically, between 3 to 6 months and between 9 to 12 months after implementation. However, the treatment group and the control group do not meet the command trend assumption. Considering the influence of implementation of combined real estate tax on January 1, 2016, the difference in difference in differences (DDD) method is used to address the problem. In further research, evidence shows that the relaxation of mortgage loan regulations had a negative but not significant impact on housing price, and the implementation of the policy may not be effective. in certain areas of Taipei and New Taipei City.