從勞動所得估計臺灣的人力資本生產與投資

THE ESTIMATION OF HUMAN CAPITAL PRODUCTION AND INVESTMENT FROMEARNINGS

本研究根據Ben-Porath （1967）的「生命週期勞動所得極大化的人力資本投資模型」， 建立可被估計的勞動所得函數， 實證探討臺灣勞工的人力資本累積及其影響因素。採用1996年至2003年行政院主計處「人力運用調查」的男性個體合併資料， 實證結果顯示學歷愈高者， 其學習能力愈強， 其所面對的借貸利率或折現率愈低，且其所擁有的人力資本或知識技能的折舊率也愈低，因而其對於人力資本的投資愈多， 故其勞動所得愈高。因此， 除了有關的財政措施外，改善弱勢者的學習能力與學習環境，提供低廉便捷的職業訓練和訓練貸款或補助，乃成為解決貧富差距的積極手段。

An empirically estimatable age-earnings profile is built based on the Ben-Porath earnings-maximizing life cycle model of human capital accumulation. The earnings profile explicitly links labor earnings and human capital investments so as to estimate the scale parameters of the human capital production function and the rates of discount and human capital depreciation, which are the crucial factors in determining the optimal time path of human capital investment. Making use of household data taken from the May 1996–2003 Manpower Utilization Surveys of Taiwan, those who are more educated are found to have a higher learning ability (i.e., endowed ability to produce additional human capital) but with a lower depreciation rate and a smaller discount rate. The empirical finding not only helps explain why the more educated investmore in human capital so as to have a greater capacity of earnings, but also carries the implication that in addition to the current fiscal instruments, providing the poorwith better learning environments and more accessible training programs, accompanied by lower training costs or higher training subsidies, is an active labor market means to improve the unequal distribution of wealth.