世界应为强美元时代做好准备

Preparing non-American markets for a strong greenback is not Janet Yellen’s job

对于美联储(Fed)主席珍妮特耶伦(Janet Yellen)来说，令美国以外市场为美元的强势做好准备，并不是她的本职工作。

As a symbol of how the US punches above its weight, nothing beats the pre-eminence of its currency. The US may account for just a fifth of global gross domestic product, but dollar assets make up three times as great a proportion of global reserves. Most commodity trading uses the greenback as the medium of account.

要寻找一个美国“勉为其难”的象征，没有什么能比美元的超重要地位更合适了。美国的国内生产总值(GDP)可能只占了全球总量的五分之一，美元资产占全球储备资产的比例却是上述比例的三倍。绝大多数大宗商品交易，是把美元作为记账媒介的。

This influence is telling. A working paper from the Bank of International Settlements found almost $8tn of dollar credit issued to non US borrowers. More recently the IMF pointed out how past episodes of dollar strength have coincided with a rash of emerging market crises. Now that the greenback is surging again — the dollar index is up 20 per cent since last autumn — the implications are moving into focus.

这种影响显而易见。国际清算银行(BIS)的一份工作报告发现，发放给美国以外的借款方的美元信贷接近8万亿美元。在更近一些时候，国际货币基金组织(IMF)曾指出，过去美元多轮强势行情，与新兴市场的多次危机，是同步发生的。如今，美元汇率再次猛涨——自去年秋季以来美元指数已上涨20%，它的影响正日渐受到关注。

First, some perspective is in order. Although the dollar index rose from 80 in October to 100 in March, such price action is run-of-the-mill when examined over a longer period. Between 1981 and 1985, the same index soared from 90 to 160, before a co-ordinated international effort pushed it all the way back within three years.

首先，某些观点认为这种波动很正常。尽管美元指数从去年10月的80上升到了今年3月的100，但从更长时期来看，这样的汇率波动并不起眼。在1981年到1985年期间，美元指数曾经从90猛涨至160，之后才在国际社会一致努力下在三年内被全力压了回去。

Dissecting the dollar is something of an art; a bet on its strength can reflect confidence in the US, or darkening clouds elsewhere and a rush to safe assets. The same IMF paper has shown that rising US rates are beneficial when they reflect optimism about growth, but not if driven by tighter money. On many occasions dollar strength has coincided with fears about growth; last autumn, for example, a spell of global deflation may have helped propel the dollar on its recent run. Of late, attention has focused more closely upon how well the US is doing.

美元的剖析是一种艺术：押注美元走强可以反映出对美国的信心，或者反映了其他地区的乌云密布以及对安全资产的抢购。IMF同一份报告显示，如果美国加息反映了对增长的乐观看法、而并非出于收紧货币政策的动机，那么它就是有益的。许多时候，美元走强之时，也是人们对增长产生担忧之时。比如，去年秋天一轮全球通缩，或曾对美元近期汇率上升起了推波助澜的作用。最近，美国的经济表现已经吸引了更多注意力。

Indeed, it is striking how US monetary policy pays little direct attention to the dollar’s globe-trotting role. Peruse Federal Reserve statements, or recent comments by its chair Janet Yellen, and you will struggle to find much reference to the world beyond US borders. Ms Yellen is focused on the data, but the data in question is all domestic: unemployment, inflation and GDP. The global economy only matters insofar as it might impact upon the US. This week GDP revisions strengthened the chance of a rise in the rate some time before Christmas.

事实上，令人吃惊的是，美国的货币政策几乎从未直接关注过美元的全球流动角色。仔细阅读美联储声明或美联储主席珍妮特耶伦近期的言论，你会很难找到太多提及美国境外世界的语句。耶伦十分关注数据，但她关注的都是美国国内数据：失业率、通胀率和GDP。只有在可能影响美国的情况下，全球经济才会得到重视。本周美国对GDP的修正，提高了在圣诞节前某个时候加息的可能性。

One might expect the Fed to worry more about the strength of its currency, particularly given evidence it has hit the profits of US foreign subsidiaries. But the US is a fundamentally closed economy where domestic demand conditions outweigh those from overseas. Instead, if anyone is worried about the effect of a strong dollar, it is the IMF, which recently warned of “significant and abrupt rebalancing of international portfolios” should the Fed raise rates. A further reason for the dollar’s strength is confirmation of a lack of credible alternatives. Those Cassandras fretting about how monetary ease damages the dollar’s reserve currency status fail to appreciate how this is built not on its strength but its depth. Dollar assets are pervasive and easily sold.

有人可能会预计，美联储对美元走强更担心一些，尤其是有证据表明美元走强已伤及美国驻外分公司的盈利。但是，美国从根本上说是一个封闭经济体，其国内需求状况的重要性压倒了来自境外的需求。相反，如果说有谁担心强势美元的影响，那就是IMF。最近，IMF曾警告说，一旦美联储加息，“国际组合资产将发生大幅度、突然的再平衡”。美元走强的一个深层次原因，是人们确信美元缺乏可靠的替代品。那些预言宽松货币政策会毁了美元储备货币地位的预言家们，未能认识到美元的这种地位并不是建立在其强势汇率上，而是建立在其深入渗透上。美元资产无处不在，能够轻而易举地抛售出手。

China’s efforts to prop up its stock market — including trading suspensions and printing renminbi to chase a market level — shows how far it has to go. Nor can the euro mount a challenge when the ECB appears politically hampered from dispensing cash in a crisis.

中国支撑股市的努力——包括为追逐某一市场点位而停牌或印钞，显示了中国在不得已的情况下走了多远。而欧洲央行(ECB)在危机中撒钱之举似乎也遭遇了政治上的阻碍，这令欧元很难对美元构成挑战

In the words of an influential monetary thinker, “never reason from a price change”. What matters is not a currency’s price, but the forces driving it. At present, the dollar is strong because the US is too. Notwithstanding the IMF’s concern, Ms Yellen’s disregard for conditions outside of the US is unlikely to budge. Nor should it. The next rise in US rates will be the most telegraphed in the Fed’s history. There will be no excuse for a tantrum.

用一位很有影响力的货币思想家的话说，“永远不要理性分析价格变动”。重要的不在于货币的汇率，而在于推动汇率波动的因素。目前，美元的强势是由于美国经济的强势。尽管IMF对加息存在顾虑，耶伦无视美国以外状况的态度不太可能改变，也不应该改变。美国下次加息，将成为美联储历史上传达最充分的加息。对此，人们没理由表示不满。