马克思主义回归？贫富差距争论回到原点

    法国经济学家托马斯•皮凯蒂这些天来过得相当舒服。上周三晚上，经济学家保罗•克鲁格曼和约瑟夫•斯蒂格利茨都高度评价了皮凯蒂撰写的《21世纪的资本》（Capital in the Twenty-First Century）——两人都属于全球经济学界最知名的群体，一共获得过三次诺贝尔经济学奖。

    也许，皮凯蒂更愿意看到这本让他这么受关注的书给人们带来好一点儿的消息。但经济学家成名的原因往往不是告诉公众一切安好。这本600多页的书当然也不会传递出这样的信息——它以令人信服的方式告诫读者，过去几十年中，全球财富和收入差距扩大的局面实际上就是资本主义经济的常态，而且今后这种趋势还会继续下去。

    这本书的题目效仿了卡尔•马克思著名的资本主义批判理论。马克思认为，资本主义社会的财富集中无可避免，皮凯蒂的分析证明了这条思路的正确性。皮凯蒂采用了最近几年自己和同行们的研究成果，这些同行包括牛津（Oxford）大学教授安东尼•阿特金森和加州大学伯克利（Berkeley）分校教授艾曼努尔•赛斯。皮凯蒂用这些研究成果表明，富裕国家的收入和贫富差距正在拉大。他还指出，二战后经济领域的分配情况较为平均是一种反常现象，除非政府出台相关政策，否则这种局面就不会再次出现。

    上周三晚上，纽约市立大学（CUNY）毕业生中心举行了一场辩论会，出席者包括皮凯蒂、克鲁格曼、斯蒂格利茨以及威斯康星大学（University of Wisconsin）经济学家史蒂文•杜尔拉夫。他们对《21世纪的资本》（Capital）中的部分观点进行了提炼，同时指出了它的不足之处。

    皮凯蒂的同事们都积极评价这本书。克鲁格曼把它誉为经济学领域的“统一场理论”，并称其中的研究融合了经济增长、资本和劳动力之间的收入分配以及收入差距。斯蒂格利茨对这本书也持同样的观点。他说，美国实现了人们在各个阶层之间的流动，如果这本书以美国社会的这个优点为基础，就无法让美国人注意到贫富差距正在扩大。但美国的社会流动性接近全球最低水平。

    杜尔拉夫充当了辩论会上的批评者，他从更为技术性的层面指出了皮凯蒂论述中的漏洞，比如皮凯蒂不同意工资的“边际产品理论”（这项理论的基本内容是，工人得到的报酬取决于他们对商业企业的边际贡献），但他没有提出其他理论来予以替代。杜尔拉夫还说，皮凯蒂应该花更多的时间来探讨造成贫富和收入差距拉大的原因是否应该是技术，而不是资本主义本身。

    和保守派经济学家格雷格•曼昆以及凯文•哈西特提出的观点一样，杜尔拉夫的意见丝毫不能改变这样一个事实，那就是，富裕国家的税前收入和贫富差距正在迅速扩大。举例来说，曼昆认为政府补贴、社会保障和福利等因素提高了人们的税后收入，因此，皮凯蒂列举的贫富差距拉大证据不应该受到重视。但这些因素恰恰表明，政府已经开始通过重新分配财富来解决贫富差距扩大的问题。

    皮凯蒂认为，需要通过在全球范围内征收财富税来缩小贫富差距。对此，来自美国企业研究所（American Enterprise Institute）的凯文•哈西特提出了最有意思的反驳意见。哈西特指出，过去二、三十年来，全球贫富差距缩小的幅度和富裕国家贫富差距拉大的幅度相仿，如果在全球范围内研究这个问题，那么在贫富差距缩小的情况下似乎没有必要征收财富税。哈西特还认为，要点在于，发达国家的人们不要以自身为中心来观察整个资本主义世界，他们不应该忽视这样一个事实，那就是30年来资本主义体制让如此之多的人摆脱了贫困。

    但对皮凯蒂的所有批评都没能证明各个国家的税前收入和贫富差距没有扩大。换句话说，这本书已经让争论的焦点从贫富差距是否带来了问题发生了转变，变成了我们究竟应该怎么应对贫富差距。（财富中文网）

    译者：Charlie

    Life's pretty good these days for French economist Thomas Piketty, who spent Wednesday evening having his book, Capital in the Twenty-First Century, lavishly praised by two of the world's most famous economists -- Paul Krugman and Joseph Stiglitz -- who just happen to own three Nobel Prizes between them.

    Piketty would probably prefer that the book that is garnering him such attention were the bearer of better news. But economists don't tend to gain renown by assuring the public that everything is A-Okay. That is certainly not the message of Capital, a 600-plus page work that convincingly warns readers that rising global wealth and income inequality over the past generation is actually the norm for capitalist economies, and that we should expect that trend to continue in the years to come.

    The title of the book is an allusion to Karl Marx's famous critique of capitalism, and Piketty's analysis shows that Marx was right to believe that wealth concentration would inexorably increase in capitalist societies. Piketty draws upon work he and colleagues like Anthony Atkinson of Oxford and Emmanuel Saez of Berkeley have done in recent years to show that income and wealth inequality are increasing in the rich world, and to argue that the more egalitarian economic distribution seen after World War II was an anomaly that we can't expect to return to unless we implement government policies to bring it about.

    A debate on Wednesday evening at CUNY's The Graduate Center featuring Piketty, Krugman, Stiglitz, and University of Wisconsin economist Steven Durlauf helped distill some of the ideas presented in Capital, and to critique its weaker points.

    Piketty's colleagues were quick to praise the book. Krugman lauded it as a "unified field theory" of economics which joins together the study of economic growth, the distribution of income between capital and labor, and income inequality. Stiglitz was equally taken by the work, arguing that Americans would not be bothered by increased inequality if it were based on merit within a society that enables class mobility. But the U.S. is near the bottom when it comes to social mobility.

    Durlauf played the role of the critic in the debate, poking holes in some of the more technical aspects of Piketty's argument, like his dismissal of the "marginal product theory" of wages (which basically asserts that a worker is paid based on his marginal contribution to a commercial enterprise) without suggesting some theory to replace it. He also suggested that Piketty should spend more time thinking about whether technology could be the reason, rather than capitalism itself, for growing disparities in wealth and income.

    This critique, like those that have been offered by conservative economists Greg Mankiw and Kevin Hassett, doesn't do anything to challenge the evidence that pre-tax income and wealth inequality is growing very quickly in the rich world. Mankiw, for instance, has argued that things like government subsidies, social security, and welfare have increased people's after-tax income, so Piketty's evidence of rising inequality shouldn't be taken seriously. But such programs just show that the government is already responding to increased inequality by redistributing wealth.

    The most interesting argument against Piketty's idea that a global wealth tax is needed to combat inequality comes from Kevin Hassett of the American Enterprise Institute. He points out that the rise in inequality in the wealthy world over the past generation has been matched by similarly striking reductions in global inequality, and if we are studying this issue on a global scale, this reduction in inequality makes the need for a global wealth tax seem unnecessary. Hassett also believes it's important for those of us in the developed world to not take a self-centered view of global capitalism, and that we should be hesitant to mess with a system that has brought so many people out of poverty over the past 30 years.

    But none of Piketty's critics have been able to disprove the rise in pre-tax wealth and income inequality on a national level. Capital, in other words, has shifted the debate from the question of whether inequality is a problem to what exactly we should do about it.