为何加强教育也无法解决收入不均问题
假设你认同这样一个令人信服的数据分析：近几十年里，收入不均现象在美国及大多数先进国家一直愈演愈烈；同时也假设你并不想通过政治领域的分裂措施来对抗收入不均现象，譬如对富人加税，或者加大社会福利力度。
此外还有一种貌似可信的办法，既能够绕开那种分裂思维，又能够解决收入不均的加剧，那就是加强教育，从而让更多的美国人能够从21世纪的经济进步中受益。这是一项保守派、中间派和自由派都能泰然支持的政策。毕竟，有谁会不喜欢更强大的教育系统呢？但是一篇新论文却阐述了这张算盘为何打不响——至少它无法消弭巨富阶层与其他民众之间的贫富差距。
布拉德·贺什本(Brad Hershbein)、梅丽莎·科尔尼(Melissa Kearney)和劳伦斯·萨莫斯(Lawrence Summers)提供了一个简单的模拟小实验，为大家演示教育在对抗收入不均现象上的局限性。简言之，更高的学历对于中低收入的美国人而言是条喜讯，这能 提升他们的薪资水平，加强他们的经济保障。只是这并不等同于如何有意义地缓解收入不均的问题，而后者当前的驱动力来自于收入分配最顶层人口的急剧向上流 动。
更加值得玩味的是，这项研究出自萨莫斯先生之手，他是前任财政部 长，很难被归类为"仇富派"的勇士。该研究的结果由汉密尔顿项目(Hamilton Project)发布，这是一个中间派的研究小组，由华尔街资助，致力于针对美国的种种难题，寻找能够同时团结左右两派的第三类途径对策。
大学毕业生人数增加，将会带来最低工资水平的上涨，但在减少贫富差距方面却效果甚微。图为普林斯顿大学校园。
Mark Makela for The New York Times
在他们的模拟实验中，他们假定处于黄金工作年龄的未受本科教育者中，有10%突然获得了本科或本科以上学历，这将导致高等学历劳动者所占比例出现前所未有的提升。
他们假定，这些学历有所提高的劳动者的薪资金额，将从原有水平调整至原有本科学历者的同等水平，再减去一个调整金额，因为劳动力市场中的本科学历者人数增加，可能会引发这一人群工资水平的轻微下降。
毋庸置疑，在这个劳动者的学历水平经过提高的模拟世界中，中等收入劳动者的收入出现了增长――1名收入排在第50百分位的劳动者，2013年收入的模拟值为37,060美元，较现实世界中34,000美元的实际收入水平，增长了9%。
但是这种学历水平的提高，不过是让这位排名第50百分位的劳动者， 更加接近他在1979年时的通胀调整后收入水平即37,838美元而已。另一方面，模拟实验中排名第90百分位的劳动者继续拥有（实际上会有所增加）过去 34年来最大幅度的收入增益。第90百分位劳动者的2013年年收入较1979年时的75,700美元出现攀升，无论是实际值，还是学历水平提高后的模拟 值，均超过100,000美元。
综合计算后，常被用于衡量收入不均程度的基尼系数，在这种学历水平出现大幅提高的情境中，却仅从0.57下降到了0.55。与1979年时的0.43相比，依然要高出许多。
这些结果中的任何一条，都没有暗示大家不需要更发达的教育系统。在三位作者的模拟实验中，中等收入劳动者明显将会获得的9%收入增益，拥有十分重大的意义。
"提高无本科学历劳动者的受教育程度，将会增加他们的平均收入和就业几率，"这三位作者写道。而即便这并未令整个社会的收入不均现象减轻多少，他们发现，这样做确实能够提高收入排名在第25百分位附近的劳动者的收入（他们在2013年的收入为一年6,100美元，学历水平提高后的模拟值为8,720美元），从而切实地减轻了收入分配下半层内部的收入不均现象。
换言之，对于美国的工薪阶层而言，追求更高等更优质的学历，本身还是值得的，因为这将会改善他们的生活品质和经济前景。与此同时，收入不均是一个更深层次的问题，各方的潜在对策依然存在意识形态上的分裂。
本文最初发表于2015年4月1日。
翻译：薄锦
Why More Education Won't Fix Economic Inequality
Suppose you accept the persuasive data that inequality has been rising in the United States and most advanced nations in recent decades. But suppose you don't want to fight inequality through politically polarizing steps like higher taxes on the wealthy or a more generous social welfare system.
There remains a plausible solution to rising inequality that avoids those polarizing ideas: strengthening education so that more Americans can benefit from the advances of the 21st-century economy. This is a solution that conservatives, centrists and liberals alike can comfortably get behind. After all, who doesn't favor a stronger educational system? But a new paper shows why the math just doesn't add up, at least if the goal is addressing the gap between the very rich and everyone else.
Brad Hershbein, Melissa Kearney and Lawrence Summers offer a simple little simulation that shows the limits of education as an inequality-fighter. In short, more education would be great news for middle and lower-income Americans, increasing their pay and economic security. It just isn't up to the task of meaningfully reducing inequality, which is being driven by the sharp upward movement of the very top of the income distribution.
It is all the more interesting that the research comes from Mr. Summers, a former Treasury secretary who is hardly known as a soak-the-rich class warrior. It is published by the Hamilton Project, a centrist research group operating with Wall Street funding and seeking to find third-way-style solutions to America's problems that can unite left and right.
Increasing the number of college graduates would raise wages at the lower end of the scale, but would do little to lessen economic inequality. Here, Princeton's campus.
Mark Makela for The New York Times
In their simulation, they assume that 10 percent of non-college-educated men of prime working age suddenly obtained a college degree or higher, which would be an unprecedented rise in the proportion of the work force with advanced education.
They assume that these more educated men go from their current pay levels to pay that is in line with current college graduates, minus an adjustment for the fact that more college grads in the work force could depress their wages a bit.
There is no doubt that in this simulated world with a more educated labor force, middle-income workers earn more — $37,060 in simulated 2013 earnings for a person at the 50th percentile, compared with $34,000 in the real world, a 9 percent improvement.
But that improvement brings that 50th-percentile worker only back closer to the inflation-adjusted level of income he enjoyed in 1979, which was $37,838. Meanwhile, the 90th-percentile worker in this simulation holds onto (and indeed improves upon) the sharp income gains of the past 34 years. Annual earnings at the 90th percentile climbed from $75,700 in 1979 to more than $100,000 in both the actual 2013 data and the simulation with higher education levels.
Add it all up, and the Gini ratio, a frequently used measure of income inequality, would decrease only to 0.55 from 0.57 in this scenario of drastic educational improvement. It would still be far higher than the 0.43 recorded in 1979.
None of this is to say that a better educational system isn't desirable. The 9 percent income gain for middle-income men evident in the authors' simulation is a big deal.
"Increasing the educational attainment of men without a college degree will increase their average earnings and their likelihood of being employed," the authors write. And even if it doesn't do much to reduce overall inequality, they find it does reduce inequality within the bottom half of the income distribution, by increasing the earnings of those near the 25th percentile of earnings (in 2013, those making $6,100 a year, compared with $8,720 in the simulation with higher education).
In other words, it's worth pursuing more and better education for working-class Americans on its own terms, because it will improve their lives and economic potential. Inequality, meanwhile, is a deeper problem, and its potential solutions remain ideologically divisive.
女权活动人士冯媛在北京一家看守所外，等待其他活动人士获释。冯媛没有被拘留。Kim Kyung-Hoon/Reuters
2014年11月26日，北京某路口。一项最新研究结果显示了中国人在一系列社会和政治问题上的看法。Kevin Frayer/Getty Images
