Gary Becker made humans the central focus of economics. The second in our series on big economic ideas.

　　贝克尔让人成为了经济学的中心焦点。我们六大经济理论的第二篇。

　　WHY do families in rich countries have fewer children?

　　为什么富裕国家的家庭生育越来越少的孩子?

　　Why do companies in poor countries often provide meals for their workers?

　　为什么穷国的公司经常给工人提供饭菜?

　　Why has each new generation spent more time in school than the one that came before?

　　为什么每一个新生代都比前一代把更多的时间花在学校中?

　　Why have earnings of highly skilled workers risen even as their numbers have also increased?

　　为什么高级技工的收入甚至在人数增长的情况下也上升了?

　　Why should universities charge tuition fees?

　　为什么大学应当收取学费?

　　This is an incredibly diverse array of questions.

　　这是一组不可置信的多元问题阵列。

　　The answers to some might seem intuitive; others are more perplexing.

　　有的问题的答案似乎是凭直觉的;有的更加复杂。

　　For Gary Becker, an American economist who died in 2014, a common thread ran throughthem all: human capital.

　　对于加里·贝克尔，这位2014年去世的美国经济学家来说，一条共同的线索把这些问题全都贯穿了起来：人力资本(human capital)。

　　Simply put, human capital refers to the abilities and qualities of people that make them productive.

　　简单地说，人力资本指的是使之具有生产力的人的能力和素质。

　　Knowledge is the most important of these, but other factors, from a sense of punctuality to thestate of someone’s health, also matter.

　　知识是其中最重要的。但是，从守时观念到健康状况等其他要素也非常重要。

　　Investment in human capital thus mainly refers to education but it also includes other things—the inoculation of values by parents, say, or a healthy diet.

　　因而，人力资本的投资主要指向教育，但是也包括其他东西。如，来自父母的价值观灌输，或者是健康的饮食。

　　Just as investing in physical capital—whether building a new factory or upgrading computers—can pay off for a company, so investments in human capital also pay off for people.

　　如同投资于实体资本——不管是建造新工厂，还是更新计算机——能够给公司有所回报一样，人力资本的投资也能给人们带来回报。

　　The earnings of well-educated individuals are generally higher than those of the widerpopulation.

　　受过良好教育的个人的收入一般都高于普罗大众。

　　All this might sound obvious.

　　这一切可能听起来是显而易见的。

　　As far back as Adam Smith in the 18th century, economists had noted that productiondepended not just on equipment or land but also on peoples’ abilities.

　　远在亚当·斯密的18世纪，经济学家就已经指出，生产不仅取决于设备或土地，还取决于人的能力。

　　But before the 1950s, when Becker first examined links between education and incomes, little thought was given to how such abilities fit with economic theory or public policy.

　　但是，在上世纪50年代，即贝克尔首次考察教育与收入间的关系之前，少有对这类能力如何进入经济理论或公共政策的思考。

　　Instead, economists’ general practice was to treat labour as an undifferentiated mass ofworkers, lumping the skilled and unskilled together.

　　相反，经济学家的惯例是把劳动力当作是一群无差别的工人来对待，把有技能的和无技能的混杂在一起。

　　To the extent that topics such as training were thought about, the view was pessimistic.

　　以至于培训之类的话题一被想到，观点就是悲观的。