经济学思想分歧不消，公众存在价值势必削弱
DISMAL may not be the most desirable of modifiers, but economists love it when people call their discipline a science. They consider themselves the most rigorous of social scientists. Yet whereas their peers in the natural sciences can edit genes and spot new planets, economists cannot reliably predict, let alone prevent, recessions or other economic events. Indeed, some claim that economics is based not so much on empirical observation and rational analysis as on ideology.
对大多数人来说，“沉闷”并不是一个讨人喜欢的形容词，但经济学家们却对它推崇备至，尤其在人们称其为科学的时候。经济学家自认是世上最严谨的社会科学家。但是，当自然科学的同仁们已经有能力改变基因、探测未知星球的时候，经济学家们却对经济会否衰退、是否有重大经济事件发生，都给不出靠谱的预测，遑论“避开”二字了。这就怪不得有人指责经济学家过分依赖经验主义和理性分析那一套研究意识形态的方法来分析经济。
In October Russell Roberts, a research fellow at Stanford University’s Hoover Institution,tweeted that if told an economist’s view on one issue, he could confidently predict his or her position on any number of other questions. Prominent bloggers on economics have since furiously defended the profession, citing cases when economists changed their minds in response to new facts, rather than hewing stubbornly to dogma. Adam Ozimek, an economist at Moody’s Analytics, pointed to Narayana Kocherlakota, president of the Federal Reserve Bank of Minneapolis from 2009 to 2015, who flipped from hawkishness to dovishness when reality failed to affirm his warnings of a looming surge in inflation. Tyler Cowen, an economist at George Mason, published a list of issues on which his opinion has shifted (he is no longer sure that income from capital is best left untaxed). Paul Krugman, an economist and New York Times columnist, chimed in. He changed his view on the minimum wage after research found that increases up to a certain point reduced employment only marginally (this newspaper had a similar change of heart).
去年十月，斯坦福大学胡佛研究所（Stanford University’s Hoover Institution）研究员Russell Roberts在推特上写到：如果告诉他一个经济学家对某一问题的观点，他可以准确预测出这个经济学家在所有问题上的立场。这篇推文甫一发出，惹得一众经济学名人博主们反应强烈，纷纷挺身捍卫学科尊严。他们并没有说大道理，而是抛出了各种经济学转变思想、应对变化的实例。穆迪评级分析机构的经济学家Adam Ozimek以Narayana Kocherlakota为例，Kocherlakota在2009-2015期间担任明尼阿波利斯联邦储备银行（Federal Reserve Bank of Minneapolis）行长，他因为错误预测了市场将出现一次强劲的通货膨胀，其主导立场随后迅速从鹰派转向了鸽派。乔治梅森大学（George Mason）经济学家Tyler Cowen则公布了一长串问题的清单，而这些都是他前后看法发生转变的问题（例如他已经不认为不上缴资本收入税是上策了）。纽约时报（New York Times）专栏经济学家Paul Krugman也帮腔说，他也有过转变观念的经历。例如他对最低工资的看法就发生了改变，因为一项调查发现大幅提高最低工资，对雇佣率下降的影响很小（这家报纸的观点也出现了相同的改变）。
Economists, to be fair, are constrained in ways that many scientists are not. They cannot brew up endless recessions in test tubes to work out what causes what, for instance. Yet the same restriction applies to many hard sciences, too: geologists did not need to recreate the Earth in the lab to get a handle on plate tectonics. The essence of science is agreeing on a shared approach for generating widely accepted knowledge. Science, wrote Paul Romer, an economist, in a paper* published last year, leads to broad consensus. Politics does not.
客观一点说，经济学家会受到各种条件限制，而自然科学家则没有。就好像经济学家不可能把经济衰退放进试管中反复测试究竟是什么原因造成的。当然，许多自然学科也同样受到条件的限制，比如地理学家不可能在实验室中再造一个地球来完成地质结构分析。科学的精髓在于用一种普遍认可的方法得出为大众所接受的理论。经济学家Paul Romer在去年发表的一篇论文中写到，科学是为了达成更广泛的一致。但政治不是。
Nor, it seems, does economics. In a paper on macroeconomics published in 2006, Gregory Mankiw of Harvard University declared: “A new consensus has emerged about the best way to understand economic fluctuations.” But after the financial crisis prompted a wrenching recession, disagreement about the causes and cures raged. “Schlock economics” was how Robert Lucas, a Nobel-prize-winning economist, described Barack Obama’s plan for a big stimulus to revive the American economy. Mr Krugman, another Nobel-winner, reckoned Mr Lucas and his sort were responsible for a “dark age of macroeconomics”.
同样的，经济学也不是。哈佛大学Gregory Mankiw教授在2006年发布的一篇有关宏观经济学的论文中这样写到：“一种新的共识已经出现，我们对经济波动已经有了最好的解读方法。”但是在金融危机引发经济衰退后，原本已达成的共识又出现了分歧。“次品经济学”(Schlock Economics)是诺贝尔经济学奖得主罗伯特·卢卡斯（Robert Lucas）给奥巴马政府的经济刺激政策冠上的名衔。而另一位诺奖得主克鲁格曼（Krugman）则称卢卡斯之辈是造成“宏观经济学黑暗时代”的祸首。
As Mr Roberts suggested, economists tend to fall into rival camps defined by distinct beliefs. Anthony Randazzo of the Reason Foundation, a libertarian think-tank, and Jonathan Haidt of New York University recently asked a group of academic economists both moral questions (is it fairer to divide resources equally, or according to effort?) and questions about economics. They found a high correlation between the economists’ views on ethics and on economics. The correlation was not limited to matters of debate—how much governments should intervene to reduce inequality, say—but also encompassed more empirical questions, such as how fiscal austerity affects economies on the ropes. Another study found that, in supposedly empirical research, right-leaning economists discerned more economically damaging effects from increases in taxes than left-leaning ones.
照罗伯特所言，经济学家容易掉入观点截然不同的敌方阵营。来自理智基金会（共和党智囊团）的Anthony Randazzo和纽约大学的Jonathan Haidt最近发起了一项调查，向一组学院派经济学家分别提出了两类问题，一类关于道德（哪种分配方式更公平，平均分配还是多劳多得？），一类是关于经济。调查结果显示经济学家对伦理的看法与其经济观点有很强的关联性。这种关联性并不局限在议题的本身，类似政府为降低社会不公应介入的程度等，同时还能应用到更多经验主义的问题上，比如节俭主义者对经济发展的不良影响。另一项研究则发现，在所谓经验主义的调查中，对税收增长破坏经济这个问题，右翼经济学家总是比左翼经济学家更为敏锐。
That is worrying. Yet is it unusual, compared with other fields? Gunnar Myrdal, yet another Nobel-winning economist, once argued that scientists of all sorts rely on preconceptions. “Questions must be asked before answers can be given,” he quipped. A survey conducted in 2003 among practitioners of six social sciences found that economics was no more political than the other fields, just more finely balanced ideologically: left-leaning economists outnumbered right-leaning ones by three to one, compared with a ratio of 30:1 in anthropology.
尽管结果堪忧，但是其他领域就没有类似的事情发生吗？Gunnar Myrdal也是诺贝尔经济学奖得主，他曾经声言任何一个学科的科学家都需要依靠设想完成研究。他笑说：“总是先有问题才会有答案的。”在2003年组织的一场针对六类社会科学从业者的调查中，研究者并没有发现经济学比其他学科政治色彩更浓厚，只是分布更均衡一些而已。虽然左翼经济学家多于右翼，达到3:1，而相比，人类学科这个比例则高达30:1。
Moreover, hard sciences are not immune from ideological rigidity. A recent study of academic citations in the life sciences found that the death of a celebrated scientist precipitates a surge in publishing from academics who previously steered clear of the celebrity’s area of study. Tellingly, papers by newcomers are cited far more heavily than new work by the celebrity’s former collaborators. That suggests that shifts of opinion in science occur not through the changing of minds so much as the displacement of one set of dogged ideologues by another.
然而，自然科学也并非思想活跃之流。在最近一项关于生命科学界学术引用的研究发现，一位成名科学家的去世总能引来大批尚未跻身学术名人界的学者竞相发表论文。值得注意的是，新人发表论文的引用量总是大大超过那些旧人（名人副手）的新作。这说明了一点，自然科学领域观点发生转变并不是因为想法变了，而是长江后浪推前浪的结果。
Agree to agree
愿意达成共识
But even if economics is not uniquely ideological, its biases are often more salient than those within chemistry. Economists advise politicians on all manner of important decisions. A reputation for impartiality could improve both perceptions of the field and the quality of economic policy.
虽然经济学并非孤立存在，然而一旦产生倾向性，其后果比起化学实验偏差要严重得多。经济学家参与政府的所有重要决定，因此达到决策皆依公平之原则会对经济观念和政策效用都有助益。
Achieving that requires better mechanisms for resolving disputes. Mr Romer’s paper decried the pretend “mathiness” of many economists: the use of meaningless number-crunching to give a veneer of academic credibility to near-useless theories. Sifting out the guff requires transparency, argued John Cochrane of the University of Chicago in another recent blog post. Too many academics keep their data and calculations secret, he reckoned, and too few journals make space for papers that seek to replicate earlier results. Economists can squabble all they like. But the profession is of little use to anyone if it cannot then work out which side has the better of the argument.
而要到达这样的高度需要一个能够合理解决争议的好机制。前文中提到的Romer发表论文谴责了许多经济学家“滥用数学”（mathiness），即用无意义的数字堆砌给出一个貌似可靠却几近无用的理论。芝加哥大学的John Cochrane在最近另一篇博客中也写到：去伪存真呼唤透明化。他说，有太多的学者对分析数据和计算方式秘而不宣，而又有太少的杂志将空间留给试图重提早期研究结果的论文。当然经济学家们可以尽情反驳他的观点，但是如果经济学分歧最后争不出个所以然的话，那么这门学科恐怕对大多数人来说都毫无用处。
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