使用民間大數據租屋資料估算消費者物價指數

自 2008 年以來台灣的房價指數平均年成長率為 6.29%，然而消費者物價指數(CPI)中的房租類指數(CPI 房租類)平均年成長率僅為 0.64%，兩者之間存在明顯落差。住宅提供人們居住的服務，因此居住服務的價格變化應被納入 CPI 中。以 2020 年為例，CPI 房租類佔整體 CPI 支出權重的 15.16%，因此偏誤的估計結果除會造成無法反映民眾真實生活成本外，也會使整體 CPI 失真，進而導致政府及中央銀行政策失去參考依據。本文使用 2008 年至 2021 年間 591 租屋網的租屋成交資料，有效樣本數為 1,073,199 筆，經利用特徵迴歸模型控制住宅異質性後，我們得到以下結果。自 2008 年至 2021 年間，利用民間資料所計算的 CPI 房租類平均年成長率介於 3.56%至 3.58% 之間，較主計總處所統計的 CPI 房租類平均年成長率 0.64%高出約 2.92%至 2.94%。此外，本文使用民間租屋資料重新計算 CPI，在不調整支出權重的情況下，結果發現平均 CPI 年成長率由 0.83%上升至 1.45%，共上升 0.62%。若重新計算支出權重，則結果平均 CPI 年成長率由 0.83%上升至 1.81%之間，共上升 0.98%。

關鍵字

消費者物價指數；租金等價法；自有住宅設算租金；特徵模型

並列摘要

Since 2008, the average annual growth rate of the housing price index in Taiwan has been 6.29%, while the average annual growth rate of the rental index (CPI rent) in the consumer price index (CPI) is only 0.64%. A significant difference between the two. Housing as a service provides people to live in, which means price changes for residential services should be accurately included in the CPI index. For example, in 2020, the CPI rent category accounts for 15.16% of the overall CPI expenditure weight. Therefore, the biased estimation results will not only fail to reflect the actual living cost of the people but distort the overall CPI. The biased result further led to economic policies made by the government and the central bank had no reference basis. This article uses the rental transaction data of 591 Rental Platform from 2008 to 2021, and the number of valid samples is 1,073,199. We obtain the following results after controlling the housing heterogeneity using the hedonic model. In the period 2008 to 2021, the average annual growth rate of the CPI rent category calculated using 591 rental platform data is between 3.56% and 3.58%, which is about 2.92 to 2.94% higher than the 0.64% average annual growth rate of the CPI rent category calculated by the Directorate General of Budget, Accounting and Statistics, Executive Yuan. In addition, this paper uses 591 rental platform data to recalculate the CPI. Without adjusting the expenditure weight, it is found that the average annual growth rate of the CPI has increased from 0.83% to 1.45%, a total increase of 0.62%. To recalculate the expenditure weight of housing rental in the CPI, the average annual growth rate of CPI rises from 0.83% to 1.81%, a total increase of 0.98 %.