1980年至2000年台灣擁屋家戶儲蓄行為之變遷：分量迴歸分析的新發現

The Changing Savings Behavior of Taiwanese Homeowners in 1980-2000: New Evidence from Quantile Regression

本文在考慮住宅租擁的選擇性之下，以分量迴歸估計台灣擁屋家戶的儲蓄函數，觀察自變數在儲蓄分配區間邊際效果的趨勢。結果發現，所得的邊際儲蓄傾向和儲蓄水準呈現正向關係，房價的財富效果則反是；兩者在儲蓄的條件分配都呈現明顯的異質性。此外，戶長年齡的儲蓄輪廓也隨儲蓄率的高低而有不同，和生命循環理論的預期並不一致。1980年至2000年間擁屋家戶的儲蓄傾向明顯增加，房價上升抑制儲蓄的財富效果也逐年擴大。相較於分量迴歸方法，傳統的最小平方法往往低估或高估不同儲蓄分量下家戶特性的邊際效果，無法完整刻劃擁屋家戶的儲蓄行為。本文透過分量迴歸，提供了關於台灣家戶儲蓄行為的新發現。

In considering the endogeneity of housing tenure choice, this study estimates the homeowners' quantile regression-based saving function by focusing on the marginal effects of the covariates across the distribution of saving. The empirical results show that most of the marginal effects of the covariates are heterogeneous across the conditional distribution of saving. In particular, the marginal propensity to save is positively associated with the distribution of saving while the reverse is true for the wealth effect of the housing price. Consequently, the age-saving profiles are not constant along with the distribution of saving, and the pattern contradicts the prediction of the life-cycle hypothesis. It is suggested that both the positive saving propensity out of income and the negative wealth effect out of the housing price of homeowners continued to increase throughout the 1980's and 1990's. From the results of the estimates of the quantile regression, this study is able to provide new evidence on the heterogeneity of the household saving propensity that is different from that presented in the existing literature.