臺灣家庭結構與外食支出變動：分量迴歸與擬真分解之應用

Family Structure and Changes in FAFH Expenditure in Taiwan: An Application of the Quantile Regression and Counterfactual Decomposition Techniques

本文利用行政院主計總處1995 年與2005 年的「家庭收支調查」資料，針對影響臺灣外食支出改變的原因進行探討。首先，分量迴歸法的分析結果顯示，影響外食支出水準的變數包括所得、家庭人口數與其結構、戶長特性等變數；當中大部分的變數之邊際效果具有異質性，表示變數的邊際效果會隨著外食支出水準的高低而有所不同。其次，本研究利用Machado 與Mata (2005) 建構在分量迴歸下的擬真分解法，進一步將家庭外食支出變動的成因進行拆解。結果顯示，臺灣家庭外食支出的變動主要可歸因於特性邊際效果的改變，而非特性分配改變的效果；以單一變數的分解結果來看，人口數的減少、都市化程度的提高以及戶長教育程度等特性，對於整體外食支出的增加具有顯著影響。

This empirical study employed the 1995 and 2005 Surveys of FamilyIncome and Expenditure to examine the changes in food-away-fromhome(FAFH) expenditure in Taiwan. Results from the quantileregression (QR) show that the influential factors include income,household size, family structure and characteristics of household heads.In addition, the impact of most factors on the FAFH expenditure isheterogeneous, indicating that their marginal effects vary with respect tolevels of the FAFH expenditure. On the basis of the QR, we also utilizedcounterfactual decomposition (Machado and Mata, 2005) to investigatechanges in the FAFH distribution between 1995 and 2005. Decomposition results reveal that the increase in FAFH expenditure from1995 to 2005 is mainly due to changes in the marginal effects of thesefactors instead of changes in their distribution. Finally, results fromexamining one factor at a time shows that the decrease in householdsize, urbanization and an increase in higher education of householdheads are crucial to the overall increase in the FAFH distribution.