One of the surprises of the Great Recession period since 2008 has been that global protection against free trade has increased only slightly, in sharp contrast to the enormous spread of trade controls during the Great Depression from 1931-34.

2008年以来的“大衰退”(Great Recession)中几件令人惊讶的事情之一是，全球反对自由贸易的保护主义仅仅略有加强，这与1931至1934年“大萧条”(Great Depression)中贸易管制的广泛蔓延形成鲜明的对比。

This period of opposition to autarky might, however, be coming under threat. Two of the three candidates left in the American presidential race are clearly protectionists. Although Hillary Clinton, the likely winner, has always leaned towards free trade agreements, she has recently hedged her previous support for the Trans Pacific Partnership because of the developing political climate.

然而，这段反对自给自足的时期或许开始面临威胁。在目前美国总统大选角逐中剩下的三位参选人之中，有两位显然是保护主义者。尽管可能的赢家希拉里•克林顿(Hillary Clinton)一直倾向于自由贸易协定，但由于政治气候的变化，近来她避免明确支持《跨太平洋伙伴关系协定》(TPP)。

Betting markets think there is a 30 per cent chance of a President Trump. He has called for a 45 per cent tariff, no less, on imports from China. His presumptive nomination, according to Edward Luce, overturns decades of Republican support for free trade.

博彩市场认为，特朗普(Trump)当选总统的几率为30%。而他竟然呼吁对从中国进口的产品征收45%的关税。爱德华•卢斯(Edward Luce)认为，特朗普成为共和党假定被提名人逆转了共和党人数十年来对自由贸易的支持态度。

And he would have a lot of sway in this area, because the usual checks and balances in the US political system do not really apply in the case of protectionist trade policy. In that field, the president has been accorded unusual powers to act, ever since President Roosevelt’s Reciprocal Trade Agreements Act in 1934.

他在这方面将拥有很大影响力，因为美国政治制度中通常的制衡，并不真正适用于贸易保护主义政策。自1934年罗斯福(Roosevelt)的《互惠贸易协定法》(Reciprocal Trade Agreements Act)出台以来，美国总统在这一领域被授予了非同寻常的行动权。

Currency “Manipulation” and Monetary Policy

汇率“操纵”和货币政策

Even under President Obama, who is clearly a convinced proponent of free trade deals, the US has been edging nearer to interference in trading relationships, under the guise of “currency manipulation”. Two weeks ago, the US Treasury reported that five of America’s largest trading partners – China, Japan, Germany, Taiwan and Korea – might be guilty of some aspects of currency manipulation, though no partner transgresses on all the criteria used by the Treasury.

即使在明显是自贸协议坚定支持者的奥巴马(Obama)总统治下，美国也一直以别国“汇率操纵”为幌子，朝着干预贸易关系的方向滑得更近。上月，美国财政部(US Treasury)报告称，美国的五大贸易伙伴——中国、日本、德国、台湾和韩国——可能在某些方面进行了汇率操纵，尽管没有哪个贸易伙伴违反美国财政部使用的全部标准。

The legislation does not specify the action that should be taken by the US government against a currency manipulator, but it clearly might include direct controls over imports into America.

法律并未说明，美国政府应对汇率操纵方采取何种行动，但措施显然可能包括对美国的进口实施直接管控。

Furthermore, the US Treasury is making it very clear that excessive reliance by foreign economies on monetary easing will not be accepted, especially if this devalues their exchange rates against the dollar. Instead, these countries are expected to use other measures to support growth, including fiscal expansion.

此外，美国财政部明确指出，将不接受外部经济体过度依赖货币宽松，尤其是如果该经济体让本国货币对美元贬值的话。相反，美国希望这些经济体使用其他措施支持增长，包括财政扩张。

In particular, Japan is clearly coming under this type of pressure prior to the G7 Summit in Shima on 26/27 May. This may explain the Bank of Japan’s decision to eschew monetary easing last month, despite clear signs of recession and returning deflation in the economy.

特别是，在5月26日至27日伊势志摩(Ise-Shima)七国集团(G7)峰会之前，日本明显感受到了这种压力。这或许解释了，尽管日本经济中衰退和通缩再抬头迹象已很明显，但日本央行(BoJ)上月为何仍决定不放宽货币政策。

These linkages between exchange rate policy and trade policy have happened many times before, notably in 1931-34. According to the definitive academic work on the spread of protection in the 1930s by Barry Eichengreen and Douglas A. Irwin, the countries that opted for direct controls over imports and capital flows were those that had decided to remain on the Gold Standard, following the UK decision to suspend gold and devalue sterling in September 1931. It was the lack of viable alternatives to stem recessionary forces, in the face of devaluation by Britain and related economies, that induced the Gold Standard bloc to resort to trade controls.

以前，汇率政策与贸易政策之间的这种联动已发生过好多次，尤其是在1931年至1934年。根据巴里•埃森格林(Barry Eichengreen)和道格拉斯•A•欧文(Douglas A. Irwin)对1930年代保护政策蔓延的权威学术研究成果，那些选择直接管控进口和资本流动的国家，正是在英国于1931年9月决定放弃金本位制并让英镑贬值之后，决定继续实行金本位制的国家。面对英国和相关经济体的货币贬值，正是由于缺乏可行的替代选项来遏制衰退压力，才导致金本位集团诉诸贸易管控。

Any comparison between then and now is certainly extreme, but it is possible to discern some shades of similarity. In early 2016, the US discovered that deflationary forces in Japan and the eurozone, alongside the consequential monetary easing by the Bank of Japan and the ECB, caused an appreciation in the dollar that the US economy could not withstand. This punctured the myth that the Federal Reserve could proceed without due regard for deflationary forces overseas.

将那时与现在比较当然太极端了，但从中可以发现部分相似之处。2016年初，美国发现，日本和欧元区的通缩压力以及日本央行和欧洲央行(ECB)随后实施的货币宽松，导致美元升值到美国经济无法承受的地步。这刺破了美联储可以不顾海外通缩力量而我行我素的神话。

Global Spread of Secular Stagnation

长期停滞向全球蔓延

Furthermore, the intellectual climate is also changing, and not just among labour market economists, who now frequently argue that trade with China has permanently damaged employment in the US. The Keynesian macro-economists who support Hillary have usually been devout free traders, but this may be changing. They have previously tended to analyse the risks from deflation and secular stagnation within closed economy models, but they are developing new multi country models which might result in a more legitimate role for protection (see this excellent explanation by Greg Ip.)

此外，知识界的氛围也在改变，而且并不仅仅发生在劳动市场经济学家当中。如今，这些经济学家频繁地声称，对华贸易已永久性地损害了美国的就业。那些支持希拉里的凯恩斯主义宏观经济学家，通常一直是自由贸易的衷心拥护者，但这种情况或许正在改变。他们过去往往在封闭经济模型内部分析通缩与长期停滞带来的风险，但他们正开发新的多国模型，这或许会赋予保护主义更大的合法性（参看叶伟平(Greg Ip)的精彩论述）。

For example, Lawrence Summers (with Gauti Eggertsson and Neil Mehrotra) has produced an analysis of “Secular Stagnation in the Open Economy”, which shows how a liquidity trap in one part of the world can be transmitted to a previously unaffected nation.

例如，劳伦斯•萨默斯(Lawrence Summers)与高迪•艾格特森(Gauti Eggertsson)和尼尔•梅赫罗特拉(Neil Mehrotra)共同撰写了分析文章《开放经济中的长期停滞》(Secular Stagnation in the Open Economy)，该文阐释了，世界某个地方的流动性陷阱是如何传导到一个此前不受影响的国家的。

Countries in deflation and secular stagnation (eg Japan, Germany and possibly China) run trade surpluses that drive capital inflows into the US and a rising dollar. The US cannot respond by cutting interest rates once the zero lower bound is reached, so it gets dragged into deflation.

陷入通缩和长期停滞的国家（如日本、德国，可能还有中国）处于贸易顺差，这推动资本流向美国，推高美元汇率。一旦利率触及零下限，美国无法采用降息手段加以应对，因此，美国也被拖入通缩。

If the surplus countries try to devalue their currencies by unconventional monetary easing, this simply transfers even more demand away from the US [1].

如果贸易顺差国家试图通过非常规的货币宽松贬值本国货币，那么这会让美国损失更多需求[1]。

The strongly preferred policy response to this dilemma is international policy co-ordination and expansionary fiscal policy, but direct interventions in trade, to switch expenditure back to the US, become more defensible than in standard models. As an example of the potential drift away from open economies and globalisation, Paul Krugman, generally a free trader, now says that he is unenthusiastic about an extension of free trade through the TPP, though he is still some way short of arguing for more protection.

面对此困境，受到强烈支持的对策是国际政策协调和扩张性财政政策，但直接干预贸易、把消费带回美国，变得比在标准模型下更有理由。保罗•克鲁格曼(Paul Krugman)总体支持自由贸易，但他可能是渐渐远离开放经济和全球化立场的一个例子。他如今表示，他对通过TPP扩展自由贸易不是太热心，不过，他还没有直接主张实行更多保护措施。

Implications for Investors

对投资者的影响

What should investors make of all this?

投资者应如何理解这一切？

First, the US political and intellectual climate has cooled towards extensions of trade deals like the TPP and the transatlantic version, the TTIP. President Obama will be fortunate to get these through, even in the lame duck session of Congress in November, when the politically “impossible” sometimes happens. The potential gains from extra trade will therefore be lost.

首先，美国政界和知识界对于扩展TPP和《跨大西洋贸易与投资伙伴关系协定》(TTIP)等贸易协议的热情已冷却下来。即便在政治“不可能事件”时有发生的11月国会“跛脚鸭”时期，美国总统奥巴马如能通过这两份协议，那也将是很幸运的。因此扩大贸易带来的潜在好处将消失。

Second, even without an outright shift towards protectionism under a President Trump, the US is making it more difficult for countries like Japan and the eurozone to combat deflation by easing monetary policy through more quantitative easing, especially if there is any suspicion that this is intended to devalue their currencies. Global monetary policy may be less able to respond to deflation threats, unless the US Fed joins in. Policy co-ordination becomes far more important than central bankers usually admit.

其次，即便当上总统的特朗普在任内不完全倒向保护主义，美国也正在让日本和欧元区等经济体更难通过加大量化宽松力度来对抗通缩，尤其是如果美国稍稍怀疑这是为了贬值其本国货币的话。除非美联储也一起行动，否则全球货币政策应对通缩威胁的能力或许会减弱。政策协调的重要性已远远超过央行官员们通常所承认的程度。

Third, the mainstream Keynesian macro-economists whose thinking normally influences the Fed’s staff are now viewing secular stagnation as an international issue, which could drag the US into a global liquidity trap, even if America is not in such a trap now. This reduces the long term equilibrium real rate of interest in the US, as FOMC members have been recognising this year.

第三，思维通常可以影响美联储工作人员的主流凯恩斯主义宏观经济学家们，如今把长期停滞视为一个国际问题，认为这个问题可能把美国拖入一个全球流动性陷阱，即便美国目前并未遭遇这一陷阱。正如联邦公开市场委员会(FOMC)今年承认的那样，这会降低美国的长期均衡实际利率。

Fourth, in a renewed global or American recession, the “tail risk” of a major spread in protectionism could all too easily become reality.

最后，若全球或美国再度发生衰退，保护主义大范围蔓延的“尾部风险”可能非常容易变为现实。

I will discuss the economic effects of protectionism another time.

我将在另一篇文章中讨论保护主义的经济影响。