经济学家必须更努力捍卫自由贸易秩序
任何人只要看一下长期的全球贸易和经济繁荣数据, 都很难不得出它们是完美伙伴的结论。当贸易增长疲软时，全球经济也疲软;在过去一代人时间里, 贸易增长带动了经济增长。在从1960年到2010年的50年间，全球经济平均年增速约3.5%，而进口年增速为6.8%，几乎是经济增速的一倍。
With such a record of success, trade liberalisation, globalisation and openness has traditionally been a core ingredient of advice to rich and poor countries alike. With trade growing twice as fast as an economy, increasing trade growth by 1 per cent was thought to be linked to 0.5 per cent of economic growth.
有了这样的成功记录，贸易自由化、全球化和保持开放性历来备受推崇——无论是对富国还是对穷国，这几条都被认为是非常有益的。由于贸易增速是经济增速的两倍，我们认为，贸易增长1%，经济就会增长0.5%。
Although there were always disputes about the direction of causation, international organisations have bemoaned the more recent slowing of trade growth because it became associated with a long mediocre spell in the global economy.
尽管何为因、何为果一直存在争议，但近来的贸易增长放缓让各国际组织叹息，因为它与全球经济表现平庸的一段较长时期同步了。
In its September economic outlook, for example, the OECD urged countries to accelerate trade expansion to deepen global value chains and boost productivity growth. “Restoring trade intensity to its pre-crisis path, including through easing trade restrictions, would help close the shortfall of productivity growth compared with pre-crisis trends,” it said.
例如, 经合组织(OECD)在今年9月的经济展望中敦促各国加快贸易扩张，以深化全球价值链和促进生产率增长。经合组织表示：“采用放松贸易限制等措施，让贸易强度回到危机前的轨道上，将有助于缩小现在的生产率增长与危机前趋势的差距。”
The International Monetary Fund last month issued one of its regular warnings that “a shift toward protectionism would reduce trade and cross-border investment flows, harming global growth”.
国际货币基金组织(IMF)上月发出了其常规性警告之一，即“转向保护主义将减少贸易和跨境投资流动，损害全球增长”。
But this consensus around the benefits of trade are not universally held and have been challenged in recent years. Populist politicians, Donald Trump in the US and the Leave campaign in the UK, have won elections by pledging to restrict the movement of goods and people. And even among economists, trade’s natural champions, some doubt has also crept in.
但是，这种关于贸易益处的结论并未得到普遍认同，而且在近几年还受到挑战。民粹主义政客、美国的唐纳德•特朗普(Donald Trump)和英国退欧派通过承诺限制商品和人员流动赢得了选举。经济学家是贸易的天然捍卫者，然而即便在经济学家当中，也有人渐渐产生了一些怀疑。
Foremost among the critics has been Dani Rodrik, professor of international political economy at the Harvard Kennedy School. “The real case for trade is subtle and therefore depends heavily on context,” Prof Rodrik says. Noting that public opinion strongly leans towards protecting jobs and the economy through trade restrictions, he questions whether the public is really naive in its protectionist views and whether simple economics has oversold the ideas surrounding the benefits of trade liberalisation.
最主要的批评者是哈佛大学肯尼迪学院(Harvard Kennedy School)的国际政治经济学教授达尼•罗德里克(Dani Rodrik)。罗德里克表示：“倡导贸易的真正理由很微妙, 因此在很大程度上取决于环境。”他指出，舆论强烈倾向于通过贸易限制来保护就业和经济，他质疑公众的保护主义观点是否真的幼稚, 以及简单经济学是否过分吹嘘了贸易自由化的益处。
While simple economics expounds the benefits of trade, in more advanced theories, the seemingly unquestionable benefits of trade become transformed into a statement adorned by all kinds of ifs and buts, Prof Rodrik says. “This disconnect has always bothered me,” he adds.
罗德里克说，虽然简单经济学阐述了贸易的好处, 但在更高级的理论中，贸易的看似不容置疑的好处却变成了由各种“如果”和“但是”修饰的叙述。他补充称，“这种脱节始终困扰着我。”
He worries about losers from trade liberalisation, the fact that these losers are rarely offered compensation within a nation and the tendency of economics to ignore these difficult issues when advocating free trade to policymakers. “Why do economists’ analytical minds turn into mush when they talk about trade policy in the real world?” Prof Rodrik asks.
让他忧心的有如下几点：贸易自由化制造输家; 这些输家在一个国家里很少会得到补偿;在向政策制定者鼓吹自由贸易时, 经济学倾向于忽视这些困难问题。罗德里克问道：“为什么经济学家们在谈论现实世界中的贸易政策时，他们擅于分析的头脑就混乱了?”
But critics of the effect of trade, particularly on certain communities, hit hard by the entry of China into the global trading system are now extremely influential in the debate. David Autor, professor of economics at the Massachusetts Institute of Technology, has made his name by describing the effect of the “China shock” on parts of the US economy, particularly the textile industries of the old South.
但是, 批评贸易的影响的人士(尤其是在某些因中国进入全球贸易体系而遭受严重冲击的社会当中)现在在辩论中极具影响力。麻省理工学院(MIT)经济学教授戴维•奥特尔(David Autor)因描述 “中国冲击”对美国部分经济领域(特别是旧南方的纺织业——旧南方指美国内战之前的南方)的影响而声名鹊起。
His research shows that the adjustment in local labour markets is glacial with wages, worker numbers and unemployment rates continuing to be affected at least a full decade after the China trade shock commences.
他的研究表明, 当地劳动力市场出现深幅调整，而且至少在中国贸易冲击开始整整十年后，工资、工人数量和失业率还在受影响。
More mainstream trade economists are not impressed by suggestions these criticisms are new. Speaking at a World Trade Organization forum in September, Paul Krugman, the Nobel Prize-winning trade economist hit back.
有人认为这些批评是新事物，更主流的贸易经济学家对这种看法不为所动。诺贝尔奖得主、贸易经济学家保罗•克鲁格曼(Paul Krugman)在今年9月的世界贸易组织(WTO)论坛上发表演讲时进行了反击。
“Textbook economics never said that growth in international trade was painless,” he said. “I wrote the textbooks so I know we always said there were distributional effects, there were losers, not countries, but people within countries.” He admitted that losers were never adequately compensated even though the textbooks said this was possible.
他表示：“经济学教科书从未说过国际贸易的增长不会伴随痛苦。我写的这些教科书，所以我知道我们总是说，贸易会影响收入分配，会制造输家——不是指国家，而是指国家里的某些人。”他承认，输家从未得到足够的补偿，即使教科书上说补偿他们是可以做到的。
But Prof Krugman wanted to extinguish any idea that the solution to trade’s downsides was a return to protectionism and trade barriers. “Turn our back on trade now, that would be highly disruptive,” he said.
但克鲁格曼不希望有任何人认为，解决贸易负面作用的办法就是退回保护主义、重设贸易壁垒。他说：“现在抛弃贸易将会造成极大的破坏。”
“There is an old joke about the motorist who runs over a pedestrian and says, ‘I’m sorry, let me fix that and so he backs up and runs over him again.’ That’s what a move to protectionism would do.”
“有一个老段子说的是，某人驾车撞倒了一个行人，于是说，‘对不起，让我来解决这个问题，于是他倒车，再次从行人身上碾了过去’。退回贸易保护主义的做法无异于此。”
For the future, most economists agree that there is a need to defend economies against populist political forces suggesting an easy answer in protectionism, whether it is building a wall to keep Mexicans out of the US or dismantling the North American Free Trade Agreement. But they also think that over are the days of simply saying trade liberalisation is good for you and you should take more of the medicine.
就未来而言，大多数经济学家认为有必要保护经济，反对民粹主义政治力量提出的保护主义的简单化答案——无论是建造隔离墙以阻止墨西哥人进入美国，还是废除《北美自由贸易协定》(North American Free Trade Agreement)。 但他们也认为，简单地说贸易自由化有好处、你应该多推行这种政策的日子已经一去不复返了。
US textile factories are not coming back, but as trade and technology threaten to disrupt many industries, there is likely to be less of a knee-jerk reaction in favour of creative destruction. Trade is still likely to grow faster than global output, but the go-go days of globalisation are probably over and substituting foreign for domestic production is unlikely to be the engine of future growth.
美国的那些纺织厂不会回来，但在贸易和技术可能颠覆许多行业之际，人们的本能反应不太可能是支持创造性破坏。贸易增速仍可能超过全球产值，但全球化迅猛发展的时代很可能已经结束，将生产外包给外国工厂不太可能成为未来增长的引擎。
Economics is up for the challenge, according to Prof Rodrik. Calling for close and empirical analysis of the problem, he says: “The economics we need is of the “seminar room” variety, not the “rule-of-thumb” kind”.
罗德里克表示，经济学准备好了迎接这种挑战。他呼吁对这个问题进行认真的实证分析，并表示：“我们需要的是‘研讨型’经济学，而非那种‘经验型’经济学。”
