高等教育擴張的所得衝擊：擴張時點前後的就業世代比較

The Income Impact of the Higher Education Expansion: Comparing the Different Employment Generations Before and After Expansion

許多國家經歷高等教育快速擴張後，出現高等教育人才供過於求與所得倒退的現象，然高等教育擴張對勞動所得影響的研究仍相當有限。本文以台灣高等教育擴張為研究對象，採用台灣家庭收支調查資料庫，選取鄰近擴張時點進入高等教育的三個世代樣本進行就業初期的所得變化相對差異比較。difference-in-difference迴歸模型的實證結果顯示，經歷過高等教育擴張的1980年出生世代，在進入職場之後，所得增加的幅度比未經歷高等教育擴張的1970年出生世代所得增加程度低，顯示高等教育擴張之後，個人就業初期的所得增加幅度相對減少。而高等教育擴張使學歷價值出現稀釋效果，未經歷擴張的1975年出生世代在高等教育擴張開始的初期進入勞動市場，其所得增加的幅度與1980年出生世代並無顯著差異，即高等教育擴張前的「末世代」與擴張後的「首世代」受到相同的衝擊。

Many developed countries suffered the troubles of excess high-educated-labor supply and income-retrogression after their rapid expansion of higher education. However the labor income evaluations for higher education expansion policy are still not enough. This paper explores the policy of Taiwan’s higher education expansion by using the data of the Taiwan Family Income and Expenditure Survey to compare three generations, who are entering labor market around the expansion point, and observing their relative changes in the initial labor income. According to our difference-in-difference model regression results, it was found that the increase in income for the generation of the 1980 was lower than that of the 1970. This result implies a substantial higher education expansion reduces the income flows of younger generations. In addition, such educational expansion led to a dilution effect of educational qualifications, so that the 1975 generation who entering universities closest to the policy-making point showed similar results to those of the 1980 generation who entering universities just after the expansion of higher education. Therefore, the final generation before the expansion of higher education and the first generation after expansion were similarly affected.