翻译Reality cheque.docx

自由贸易现实支票安格斯迪顿因将经济学应用于现实世界而获得诺贝尔奖 2015年10月17日 来自经济学人10月12日早上6:10美国东海岸普林斯顿大学经济学家安格斯迪顿接到了一个带着瑞典口音的电话，这个电话里的人为了使他相信这不是个恶作剧的急切声音让他担心这恰恰是一个恶作剧。其实，这是毫无必要的。诺贝尔委员会已为他针对消费、贫困和福利的分析授予了他 诺贝尔经济学奖。这个奖项为他利用数据推翻草率假设，重新构思如何衡量世界，且与微观经济学和宏观经济学相互交织的整个职业生涯庆贺，他甚至有一个以他名字命名的悖论。在金融危机使得贫困和不平等的争议风行之前很久，这个至今69岁的老教授就在研究这个问题了。他进行了一次家庭调查， 改变了20世纪80年代发展经济学的糟糕状况，当时，发展经济学已深陷数据模糊、理论自相矛盾的状况。他研究了穷人收入增加时多消耗多少；收入萎缩时多得多少保障，更广泛地探索收入与健康之间的关系问题。他相关不平等理论具有典型特征。他把不平等当成成功的产物因为有穷人就必有富人。但是，他并不是社会精英的支持者，相反，他认为研究数据应当揭示让成千上万穷人致富的方法。尽管，他与不平等相关的作品可能最吸引人的眼球，但委员会还是强调了他早期一系列惊奇贡献。第一，他的研究促进经济学家估算需求方法的进步，对于理解政府调整税收、超市促销商品等政策来说，人们知道如何应对价格变化是至关重要的。在迪顿的研究之前，经济学家 使用的是简单模型，这种模型创设了许多关于人们消费模式的严苛假设，但是，仔细推敲，会发现其实这些模型中的假设与人们现实生活中如何应对价格变化是自相矛盾的。迪顿及时补救了这种现象，他提出旧的模型可能因为假设过于死板而不适用，他和他的同事约翰米尔鲍尔提出了一个新的解决这个问题的方法。这套系统被他们贴切地命名为近乎完美需求体系，与旧的模式相比，它的优点在于便于估算，缺少那些千遍一律的假设。例如，在之前的模拟中，不管这个人是富有还是贫穷，他的需求与收入同步增长，而新的方法表明不同的收入水平的人对需求有不同的反应，1%的收入增长可能会使穷人对生活必需品的需求增长2%，而使富人对生活必需品的需求仅仅增长0.1%。其他经济学家多次引用迪顿和米尔鲍尔的这篇论文，在他们提议的方法的基础上衍生出了其他方法。尽管迪顿他们的理论大获全胜，然而，两人始终是这个模型最严厉的批评者队伍中的一员正如其名称所示，他们并未打算提供完美的答案，只是想为未来的研究提供指导。诺贝尔委员会还强调迪顿的第二项成就在于沟通宏观经济学和微观经济学，特别是理解消费与收入的关系。这种关系至关重要，收入与消费之间的差距即决定了储蓄水平，反过来说，储蓄存款决定了经济体的投资力度，并最终决定社会未来财富。在迪顿理论提出之前，其他宏观经济学家使用个人行为模式去阐释消费的整体波动性要比收入小。米尔顿.费里德曼的“永久收入假设”便是此类假设之一，他认为人们在面对短暂的收入波动时会平缓消费的步伐，该理论预测，应对一次性收入激增，人们会把额外资金储存以备不时之需。这种理论与整体消费比整体收入更加平缓的观测报告恰好吻合。米尔顿范例之失但是经过迪顿的研究揭示了这些只能作为草率理论。首先，他指出在费里德曼模型中对收入与消费的关系的研究依赖打击经济体的各种收入冲击波。如果一次收入的增长预示着未来将会有更多的收入 ，那么，在费里德曼模型中，最理性的人应当预期到未来收入的增长，其消费相对于初期收入增长时也会有所提高。在这种情况下，消费的波动幅度应该大于收入，而不是恰恰相反。 所以，事实证明，迪顿再对总收入数据作了更加详细的调查后，发现这些数据并不能证明消费平滑轮，他的微观经济学理论与他的经验观测值相符。同时还暗示了收入应该比消费更平缓。这一理论与宏观经济学家原本试着去解释的理论形成对照。这种前后矛盾的理论就是迪顿悖论。除了这三项对于我们理解世界有重要意义的特殊贡献之外，迪顿还为准备一展抱负的经济学家提供了三个教诲。首先，理论应当与数据一致，但如果不一致，也不要丧失信心，困惑和矛盾有助于促进创新；其次，正常标准并不意味着足够优秀，唯有通过理解人们之间的差异，我们才能看透整体；最后，衡量方法至关重要，换做迪顿的话就是“没有定义和支持证据，发展就可能受阻”，用米尔鲍尔的话说就是，迪顿的获奖是“基于证据的经济学胜利”。附原文Free exchangeReality chequeAngus Deaton wins the Nobel Prize for bringing economics back to the real world Oct .17th 2015 From The EconomistAT 6:10am on October 12th, Angus Deaton, an economist at Princeton University on Americas east coast, picked up the phone to a Swedish voice. The voice was so concerned to persuade him that this wasnt a prank call that he started to worry it was precisely that. No need. The Nobel committee had awarded him the Sveriges Riksbank Prize in Economic Sciences, “for his analysis of consumption, poverty, and welfare”. The prize celebrated a whole career, in which he has used data to overturn sloppy assumptions, reimagined how we measure the world, and intertwined microeconomics and macroeconomics. He even has a paradox named after him.The 69-year-old professor was working on issues of poverty and inequality long before the financial crisis made them voguish. As a designer of household surveys, he helped transform development economics from its sorry state in the 1980s, when it was stuck in a rut of murky data and unverifiable theories. He has explored how much more the poor eat when they get more income, how well insured they are when their earnings shrivel and, more broadly, the relationship between health and income growth. His thinking on the topic of inequality is typically textured. He frames it as a product of successfor there to be have-nots, there must be havesbut he is not a cheerleader for the elite. Rather, he thinks that digging into the data reveals how to help the millions of people who have been left behind to catch up.Although his work on inequality may grab most attention, the Nobel committee also highlighted a couple of his earlier, more wonky contributions. The first was for his work in transforming the way economists estimate demand. Knowing how people respond to price changes is crucial to understanding the effects of governments tweaking taxes, supermarkets promoting products, and the like. Before Mr. Deaton arrived on the scene, economists used simple models that made rigid assumptions about peoples consumption patterns. But upon closer inspection, it turned out that the assumptions in these models were inconsistent with real-life data on how people respond to changes in prices.Mr. Deaton swooped to the rescue. He suggested that the old models might have failed because their assumptions were too severe. Along with a colleague, John Muellbauer, he proposed a new way of modeling the problem. Their modestly named “Almost Ideal Demand (AID) System” had the beauty of being simple to estimate, but without the rigid assumptions that were the undoing of the old methods. For example, in earlier models, demand was assumed to increase in lock-step with income, regardless of how rich the person was. The new approach allowed for different responses according to the level of income, so that a 1% pay boost might raise porridge demand by 2% for a pauper, but only 0.1% for a prince.The much-cited paper in which Messes Deaton and Muellbauer laid out their approach has spawned a family of extensions, devised by other economists. For all its successes, however, the pair have been among the models harshest criticsas hinted in its name, they had not intended to provide “the” answer but to guide future research.The second achievement highlighted by the Nobel committee was Mr. Deatons help in bridging the gap between macroeconomics and microeconomicsand in particular in understanding the relationship between consumption and income. This relationship is crucial. The difference between the two is the level of savings; in turn, savings determine how much an economy invests and ultimately societys future wealth.Before Mr. Deaton came along, macroeconomists used models of individual behavior to explain, why, in aggregate, consumption seemed less volatile than income. One such attempt was Milton Friedmans “permanent income hypothesis”, which supposed that people smooth consumption when they face temporary jolts to their income. In response to a one-off pay bump, this theory predicted that people would put aside some of the extra cash for a rainier day. That idea tallied nicely with the observation that in aggregate consumption looked smoother than income.Miltons paradigm lostBut Mr. Deatons work exposed this as sloppy thinking. First, he noted that the relationship between consumption and income in Friedmans model depended on the kinds of income shocks hitting an economy. If one pay rise acts as a signal that there are more to come, then the “rational” agent in Mr. Friedmans model should anticipate future increases, and spend even more than their initial income boost. In this case, consumption should be more volatile than income, not the other way round.So indeed it proved. Mr. Deaton examined the aggregate income data more carefully, and found that it did not seem to support the idea of consumption smoothing. His microeconomic theory, allied with his empirical observations about aggregate income, together implied that income should be smoother than consumpt