Finance and Economics; Free exchange; Body of evidence;
财经；自由交流专栏；关于金融危机的大量证据；
Is a concentration of wealth at the top to blame for financial crises?
金融危机是否应归咎于财富向上层的集中？
In the search for the villain behind the global financial crisis, some have pointed to inequality as a culprit. In his 2010 book “Fault Lines”, Raghuram Rajan of the University of Chicago argued that inequality was a cause of the crisis, and that the American government served as a willing accomplice. From the early 1980s the wages of working Americans with little or no university education fell ever farther behind those with university qualifications, he pointed out. Under pressure to respond to the problem of stagnating incomes, successive presidents and Congresses opened a flood of mortgage credit.
全球金融危机的幕后黑手究竟是谁。各方对此问题的调查从未停止过，其中就有一种观点认为，收入不平等是造成危机的罪魁祸首。芝加哥大学的拉古拉迈·拉詹教授在他2010年出版的《断层线》一书中说，引发危机的主犯是收入不平等，而政府则充当了心甘情愿的帮凶角色。他指出，自1980年代初起，美国劳动者的收入出现了两极分化，未受过高等教育的人的工资远低于拥有大学学历者，而且二者的差距还在扩大。民众收入停滞不前成了历任政府和国会都头痛不已的老大难问题，迫于现实压力，他们作出了放开抵押贷款限制的决定。

In 1992 the government reduced capital requirements at Fannie Mae and Freddie Mac, two huge sources of housing finance. In the 1990s the Federal Housing Administration expanded its loan guarantees to cover bigger mortgages with smaller down-payments. And in the 2000s Fannie and Freddie were encouraged to buy more subprime mortgage-backed securities. Inequality, Mr Rajan argued, prepared the ground for disaster.
1992年，政府降低了对房利美和房地美的资本要求，这两家公司都是住宅信贷市场上的主要资金供给者。在1990年代，美国住房管理局放松了向借款人提供抵押担保的条件，将更多的小额首付抵押贷款也纳入了其覆盖的范围。进入2000年后，房地美和房利美在有利形势的鼓舞下购买了更多的次级住房抵押贷款证券。此后，收入不均的土壤里便结出了灾难的果实，拉詹如此说道
Mr Rajan's story was intended as a narrative of the subprime crisis in America, not as a general theory of financial dislocation. But others have noted that inequality also soared in the years before the Depression of the 1930s. In 2007 23.5% of all American income flowed to the top 1% of earners—their highest share since 1929. In a 2010 paper Michael Kumhof and Romain Rancière, two economists at the International Monetary Fund, built a model to show how inequality can systematically lead to crisis. An investor class may become better at capturing the returns to production, slowing wage growth and raising inequality. Workers then borrow to prop up their consumption. Leverage grows until crisis results. Their model absolves politicians of responsibility; inequality works its mischief without the help of government.
拉詹只是讲述了美国次贷危机事件的经过，他并没有针对金融紊乱提出某种可供解释的一般性理论。但是有人注意到，在1930年代大萧条爆发前夕的那些年，收入不平等的程度急剧上升。在2007年，占美国人口1%的最富裕人群吸收了当年全国收入的23.5%——这一比例是自1929以来的达到的最高点。2010年，两位来自国际货币基金组织的经济学家迈克尔·科夫和罗曼·朗西埃在一篇论文中构建了一个模型，显示了收入不平等是如何系统性地导致了危机的产生。投资者阶层越来越善于获取生产性收益、减慢工人工资增长速度，从而提高收入了收入不平度程度。工人们只得依靠借款来维持消费。信贷杠杆不断上升，直至以危机爆发而告终。该模型假设政治家不负担监管的责任；在没有政府介入的前提下，收入不均会产生各种危害。
New research hints at other ways inequality could spur crisis. In a new paper* Marianne Bertrand and Adair Morse, both of the University of Chicago, study patterns of spending across American states between 1980 and 2008. In particular, they focus on how changes in the behaviour of the richest 20% of households affect the spending choices of the bottom 80%. They find that a rise in the level of consumption of rich households leads to more spending by the non-rich. This “trickle-down consumption” appears to result from a desire to keep up with the Joneses. Non-rich households spend more on luxury goods and services supplied to their more affluent neighbours—domestic services, say, or health clubs. Had the incomes of America's top 20% of earners grown at the same, more leisurely pace as the median income, they reckon that the bottom 80% might have saved more over the past three decades—$500 per household per year for the entire period between 1980 and 2008, or $800 per year just before the crisis. In states where the highest earners were wealthiest, non-rich households were more likely to report “financial duress”.
最新研究表明，不平等还会以其他方式刺激危机发生。芝加哥大学的玛丽安·伯特兰和阿戴尔·莫尔斯最近发表的一篇论文研究了1980——2008年间美国各州的消费模式。他们特别关注了美国人中最富有的20%人群的行为变化如何到影响底层80%人群的消费决策。他们发现，富裕家庭消费水平的提高会引起非富裕家庭开支的增加。人们想要与收入地位相等者进行攀比的心态似乎引发了“涓滴型消费”现象的出现。非富裕家庭在他们那些有钱邻居的影响下会购买更多的奢侈物品和服务——比方说，国内航线或健身俱乐部等。他们估计，过去的三十年里，如果美国收入最高的20%人群的收入增速放缓到像中等收入者一样的水平，底层的那80%人群可能就会更多地进行储蓄——从1980到2008年，每年每户家庭能存500美元，到危机爆发前夕，每年储蓄的金额会上升到800美元。研究表明，在那些收入最高者同时也是最富裕人群的几个州中，非富裕家庭表现出“金融胁迫”症状的可能性更高。
The paper also reveals how responsive government is to rising income inequality. The authors analyse votes on the credit-expansion measures cited in Mr Rajan's book. When support for a bill varies, the authors find that legislators representing more unequal districts were significantly more likely to back a loosening of mortgage rules.
这篇论文同时也揭示了政府如何应对不断加剧的收入不均问题。两位作者分析了拉詹书中介绍的各种有关信贷膨胀措施法案的投票情况。他们发现越是来自收入不均地区的立法者，越是倾向于给放松抵押贷款政策投赞成票。
Inequality may drive instability in other ways. Although sovereign borrowing was not a direct contributor to the crisis of 2008, it has since become the principal danger to the financial system. In another recent paper Marina Azzimonti of the Federal Reserve Bank of Philadelphia, Eva de Francisco of Towson University and Vincenzo Quadrini of the University of Southern California argue that income inequality may have had a troubling effect in this area of finance, too.
收入不平等还可能引起其他方面的混乱。尽管主权债务没有直接导致2008年的金融危机，但是现在它已成为维护金融系统稳定的头号大敌。费城联邦储备银行的玛丽娜·阿兹莫提、陶森大学的伊娃·德·弗朗西斯科以及南加州大学的文森佐·夸德里尼在最近合作发表的一篇论文中指出，收入不平等可能会给主权债务这一金融领域造成不小的麻烦。
The authors' models suggest that a less equitable distribution of wealth can boost demand for government borrowing to provide for the lagging average worker. In the recent past this demand would have coincided with a period of financial globalisation that allowed many governments to rack up debt cheaply. Across a sample of 22 OECD countries from 1973 to 2005, they find support for the notion that inequality, financial globalisation and rising government debt do indeed march together. The idea that inequality might create pressure for more redistribution through public borrowing also occurred to Mr Rajan, who acknowledges that stronger safety nets are a more common response to inequality than credit subsidies. Liberalised global finance and rising inequality may thus have led to surging public debts.
他们的模型显示，一个有欠公平的财富分配机制会推高政府的借款需求。政府再将筹集的借款转移给低收入群体。在过去数年，政府的借款需求的上升恰好伴随着金融全球化的进行，这使得许多政府能够得以低廉的成本发行债券。在一份包括了22个OECD国家从1973年到2005年间数据的样本中，他们发现收入不均、金融全球化以及政府债务的上升确实处于同一步调中。拉詹也意识到了收入不平等会通过增加公共借款的形式进行财富的再分配。他认为政府在应对收入不平等问题时，合理的反应应该是加强社会安全网，而非鼓励信贷补贴。全球金融自由化和收入不平等的加剧可能是导致公共债务上升的原因。
Other economists wonder whether income inequality is not wrongly accused. Michael Bordo of Rutgers University and Christopher Meissner of the University of California at Davis recently studied 14 advanced countries from 1920 to 2008 to test the inequality-causes-busts hypothesis. They turn up a strong relationship between credit booms and financial crises—a result confirmed by many other economic studies. There is no consistent link between income concentration and credit booms, however.
经济学家中持不同观点者则怀疑收入不平等是否真应担此恶名。罗格斯大学的迈克尔·波尔多和加州大学戴维斯分校的克里斯托弗·麦斯纳研究了14个发达国家从1920年到2008年的有关的数据，对不平等引起破产的假设进行检验。他们得出的结论是，信贷繁荣与金融危机之间存在着强相关性——许多经济研究已经证实了这一点。然而，收入集中和信贷繁荣之间不存在任何联系。
Inequality occasionally rises with credit creation, as in America in the late 1920s and during the years before the 2008 crisis. This need not mean that the one causes the other, they note. In other cases, such as in Australia and Sweden in the 1980s, credit booms seem to drive inequality rather than the other way around. Elsewhere, as in 1990s Japan, rapid growth in the share of income going to the highest earners coincided with a slump in credit. Rising real incomes and low interest rates reliably lead to credit booms, they reckon, but inequality does not. Mr Rajan's story may work for America's 2008 crisis. It is not an iron law.
收入不平等偶尔会伴随着信贷扩张而产生，美国在1920年代末和2008年就经历了这种情况。波尔多和麦斯纳注意到，这并不意味着不平等与信贷之间存在着因果关系。在有的情况中，信贷繁荣似乎反倒引起了收入不平等的加剧，比如1980年代的澳大利亚和瑞典就有这种情形的发生。在1990年代的日本，收入快速集中到高收入者手中的同时，信贷却在萎缩。他们估计，实际收入的上升和较低的利率导致了信贷的繁荣，收入不平等并非诱因。拉詹的的理论或许很好地解释了美国2008年的金融危机，但它并非任何条件下都适用。