人民币对美元汇率上周突然下跌，震动全球股票市场，引起各国媒体强烈反响，包括新加坡元、韩国元、越南盾和马来西亚林吉特在内的一批亚洲货币随即下跌。随着南非兰德贬值，这场冲击也漫延到非洲。《华尔街日报》8月17日评论称，人民币贬值吓坏了中国的非洲伙伴。美国参议员罗伯特·凯西甚至敦促奥巴马政府给中国贴上货币操纵国标签。

但是，在8月17日布鲁金斯学会的发言中，艾伦·格林斯潘作了更专业的评价，他赞成中国央行最近的行动，认为这是朝建立市场导向汇率机制所采取的积极步骤。

估值过高的人民币终于接近其真正市场价值

采取最近这次行动前，中国人民银行过去几个月一直将人民币对美元每日比价定在6.11，而离岸外汇市场实际汇率低于6.20，显示官方比价明显过高。8月11日，中国人民银行基于前日约6.22的实际市场交易水平，将官定比价从前一日的6.1162调降到6.2298，贬值幅度为1.8%。当天市场上人民币汇率降到6.3以下，这说明实际汇率应该更低。第二天，人民银行再次基于实际市场价格，把人民币比价定为6.3306，第三个交易日又降到6.4010，并迅速在接下来的五个交易日里将汇率稳定在6.3915－6.3975，直到8月20日，人民币对美元累计下跌4.5%，或多或少反映了当前人民币在市场上的水平。它同时也表明，由于市场基础不充分，人民币之前的汇率是过高的。

随着人民币对美元汇率在新的水平上稳定下来，下周全球股市和汇市很可能恢复正常。

最近的人民币贬值，是汇率形成机制在完全市场化和政策性扭曲最小化方面取得重要进展的结果。这也是国际货币基金组织和美国政府一直以来要求中国做的。

问题在美元，而不是人民币 

与美元的比价是人民币汇率的基准，但它并不是人民币贬值或升值的官方标准。官方度量标准，是人民币对国际清算银行设定的一揽子货币的实际有效汇率（REER）。近几年里，人民币REER一直过高，已经难以持续下去。

主要货币的REER

          人民币     美元     欧元      日元    巴西雷亚尔 马来西亚林吉特

12/2012   106.56     97.31     96.89     101.16    84.96       101.46

01/2014   115.62    101.19    103.66    82.23     78.28       98.17

07/2014   111.52     100.49   102.58   83.88     84.65        101.19

07/2015   127.46    115.58    93.67   75.07     65.49       93.35

期间内变动幅度

12/2012   +19.6%     +18.8%    -3.3%    -25.8%    -22.9%    -8.0%

01/2014   +10.2%     +14.2%    -8.7%   -10.5%    -23.1%     -7.6%

资料来源：国际清算银行及相关统计

到2012年12月，从经常项目盈余占GDP比重和贸易盈余占贸易总额比重判断，人民币汇率应该处在一个平衡区间内。但自那时起到上月为止，人民币REER上升了19.6%，达到1994年1月国际清算银行首次纪录REER以来最高水平。相比之下，美元上升了18.8%，欧元、日元、巴西雷亚尔和马来西亚林吉特汇率同期内全部大幅下跌。结果是，人民币对美元升值0.7%，对欧元、日元、巴西雷亚尔、马来西亚林吉特分别升值23.7%、61.2%、55.1%和30.0%。显然，人民币REER已经偏离均衡水平，需要由市场向下纠正。

经过近期下跌，人民币只对美元出现贬值，但对其他主要货币仍相当坚挺。人民币REER是基于若干主要货币，其中最大权重是欧元，接下来是美元和日元。让人民币REER紧跟美元REER是不可能的。人民币对美元贬值更多是由于美元坚挺，而不是人民币疲软。

在全球货币市场上，汇率的起伏是常态。没有人抱怨欧元下跌。欧元2008年兑换1.46美元，去年兑换1.30美元，目前在1.10美元上下浮动，高盛公司预计这一水平将维持到年底。日元对美元下跌得更厉害，从2010年的83日元跌到最近的接近120日元。对此同样也没有人抱怨。那么，为什么要对人民币的贬值大惊小怪？

人民币对美元下跌最根本的原因不在于人民币本身，因为它的REER仍然非常高，而在于美元过于坚挺。美元对主要货币的名义汇率指数2014年1月只有77.1141，2015年7月达到91.6450，19个月里上升24.5%。显然，人民币不能追随美元的汇率水平。

自从与黄金脱钩以来，过去42年，美元已经表明有自己的涨跌周期。有意思的是，2009年3月到2010年10月的19个月里，美元下跌14.0%，而美国议员们并没有发出抱怨。

可以预见，由于美联储是否加息仍悬而未决，美元未来几个月将继续坚挺，从而使人民币对美元有更多贬值空间。考虑到中国经济基本面，人民币贬值将是有限的，到年底对美元降至6.50－6.60也是合理的。然而，由于美元已经充分坚挺，接下来的阶段就是美元下跌。在这个阶段，人民币对美元将再度升至6.40、6.30甚至6.20。

汇率对中美贸易影响甚微 

过去八年中美双边贸易的增长曲线显示，人民币对美元比价与双边贸易并没有很强的关联性。

相反，据美国国际贸易委员会的官方贸易统计，人民币对美元升值推动中国对美国的出口。2008年人民币再次盯住美元的时候，中国对美国的出口增长缓慢（增幅只有5.1%，而全世界对美出口增长7.5%）。2010－2014年人民币再次浮动并对美元升值，同期中国对美元的出口增速超过世界其他地区（57.5%对50.5%）。2015年上半年，人民币和美元同样坚挺，中国对美国的出口仍然增长5.9%，而世界其他地区下降了3.4%。

至于美国对中国的出口，过去18个月里增长势头迅速减弱。2014年，美国对全球出口增长2.7%，对华出口只增长1.6%。2015年上半年，美国对华出口下降4.5%，与对世界其他地方的出口下降基本同步（5.2%）。对华出口下降的原因是可寻的，在很大程度上，是农业出口急剧减少10.1亿美元，净下降38.4%，而运输设备、计算机和电子产品、化学品的出口增长4.5亿美元。这四个领域采用同样的汇率，却有截然不同的表现。因此，这些数字无法用人民币汇率来解释。根据中国官方贸易数据，今年1月到7月，中国大豆进口（主要来自美国）按价值计算比去年同期减少19.6%，尽管进口量增加了7.0%。其原因很明显，是世界市场上大豆价格出现大幅下跌。美国对全球的农业出口也显示出同样状况，在2015年上半年减少120.9亿美元，占总净出口下降的28.9%。

总之，影响中美双边贸易表现的主要因素是贸易结构和全球商品市场，而不是人民币对美元汇率。两国和两国经济界应该把关注点放在认清两国的互补领域和产品上，寻求在互利基础上可持续的稳定增长。

The sudden fall of the RMB exchange rate to the US dollar last week shocked the world stock markets and caused strong repercussions in world media. A number of Asian currencies including the Singapore dollar, Korean Won, Vietnamese dong and Malaysian ringgit fell immediately. The shock also extended to Africa as the South African rand was devalued. Wall Street Journal commented on August 17 that RMB devaluation had frightened Chinese African partners. US Senator Robert Casey has even urged the Obama Administration to label China as a currency manipulating country.

However, a more professional comment by Alan Greenspan favored the Chinese central bank's recent move, regarding it an active step toward a market-oriented exchange rate mechanism, during his speech at the Brookings Institution on August 17.

An Over-Valued RMB Finally Came to Its Real Market Value 

Before the latest move, the People's Bank of China had set the daily parity rate for RMB at around 6.11 to the dollar for months. However, the actual exchange rate on the offshore exchange market was lower than 6.20, showing a clear over-valued official parity. On August 11, the Chinese central bank lowered its parity from 6.1162 of the previous day to 6.2298, or a straight 1.8% devaluation, based only on the actual market trading level of the previous day, which was around 6.22. The market fell again that day to below 6.30, showing the fact that the actual exchange value should be even lower. On the following day, the central bank set the parity rate at 6.3306, again based on the actual market value. The parity fell slightly further on the third trading day to 6.4010, and then quickly stabilized at 6.3915-6.3975 for the following five trading days until August 20, with an accumulative fall of 4.5% to the dollar, more or less reflecting the current RMB market level. It also shows that, the previous RMB exchange rates were overvalued, due to an inadequate market base.

As the RMB stabilized at a new level to the dollar, the world stock and exchange markets will most likely return to normal next week.

The recent RMB fall has been the result of a significant step forward in its exchange-rate formation mechanism, towards a fully market-based one, minimizing the policy distortion. Such has been the requirement of the IMF, and of the US government as well.

More a Dollar Issue, rather than a RMB Issue 

The exchange rate to the US dollar, while serving as the benchmark for the RMB exchange-rate level, is not however, the official measurement of its devaluation or revaluation. The official measurement is RMB's real effective exchange rate (REER) to a basket of currencies, set by Bank for International Settlements (BIS). Over the recent years, RMB REER has been too high and could not be sustained.

REER of major currencies

                      RMB     US Dollar     Euro        Yen       B Real       M Ringgit

12/2012       106.56       97.31          96.89     101.16      84.96          101.46

01/2014       115.62      101.19       103.66      82.23       78.28           98.17

07/2014       111.52      100.49       102.58      83.88        84.65         101.19

07/2015       127.46      115.58        93.67       75.07        65.49          93.35

 Change since

12/2012       +19.6%     +18.8%       -3.3%     -25.8%      -22.9%        -8.0%

01/2014       +10.2%     +14.2%       -8.7%     -10.5%      -23.1%        -7.6%

Source: BIS, www.bis.org, and computation thereof

By December 2012, the RMB exchange rate should have already been within an equilibrium range, judging from both the current account surplus as a percentage of GDP and trade surplus as a percentage of total trade volume. However, by last month, its REER rose by 19.6% over this period, hitting the record level since January 1994, when BIS REER was first recorded, compared to the dollar's 18.8% rise. The euro, yen, Brazilian real and Malaysian ringgit all fell considerably during the same period. As a result, the RMB rose by 0.7% to the dollar, 23.7% versus the euro, 61.2% vs. the yen, 55.1% vs. the Brazilian real and 30.0% vs. the Malaysian ringgit.  Apparently, RMB's REER had deviated from its equilibrium level and needed a downward correction by the market.

After the recent fall, the RMB has only depreciated to the dollar, but still appreciated considerably against other major currencies. The REER of the RMB is based on a number of major currencies, with the largest weights from the euro, followed by the dollar and then the yen. Therefore, it is impossible for the RMB REER to follow the dollar REER. The current RMB fall compared to the dollar is an issue of the dollar's strength, rather then RMB weakness, if any.

The rises and falls are daily normal in world currency markets. There is no complaint about the euro's fall. The euro could exchange for $1.46 in 2008, and $1.30 last year, but hovers currently around $1.10, with Goldman Sachs' forecasting parity by the year end. The yen fell even more against the dollar, from 83 in 2010 to a recent close at 120. Again, there is no complaint. Why a fuss over the RMB?

The fundamental explanation for the RMB's fall to the dollar is not about the RMB, because its REER is still exceptionally high, but with the dollar, which is too strong. The nominal exchange rate index of the dollar to major currencies stood at 91.6450 for July 2015, while it was 77.1141 for January 2014, or 24.5% up over 19 months. Apparently, RMB should not follow the dollar's exchange-rate level.

However, the past 42 years since the de-pegged from gold have shown the dollar's own cycles, with subsequent rises and falls.  Interestingly, during an earlier 19-month period from March 2009 to October 2010, it fell by 14.0%. Again, there was no complaint from the US congressmen.

It can be anticipated that, with the FED interest-rate hike still pending, the dollar will continue to strengthen in the coming months, leaving room for the RMB to fall further from the dollar. Due to the economic fundamentals in China, the RMB's drop will be limited: It will still be reasonable if the RMB falls to 6.50-6.60 to the dollar by the year's end. However, with the dollar's strength fully developed, a new phase of dollar's fall will follow. During that period, RMB will most probably rise again to 6.40, 6.30 or even 6.20 to the dollar.

Exchange Rate Has Little Impact on China-US Trade 

The growth curve of China-US bilateral trade over the past 8 years does not show any strong linkages between the RMB/dollar exchange rates and the bilateral trade performances.

Ironically, according to the US ITA official trade statistics, the appreciation of the RMB to the dollar has helped Chinese exports to the US. When RMB was pegged again to the dollar in 2008, Chinese exports to the US grew more slowly (by only 5.1%, compared to 7.5% growth in the world exports to the US). During the period of 2010-2014 when RMB floated again and appreciated to the dollar, Chinese exports to the US grew faster than to the rest of the world (57.5%:50.5%). During the first half of 2015, when the RMB was as strong as the dollar, Chinese exports to the US still grew by 5.9%, while the rest of the world saw a 3.4% decline.

As regards US exports to China, there has been a fast weakening in its growth momentum over the past 18 months. In 2014, US exports to the world grew by 2.7%, but grew by a mere 1.6% to China. During the first half of 2015, US exports to China declined by 4.5%, approximately the same rate as its exports to the world (off 5.2%). The reason of its exports to China could be found, to a large extent, in the sharp fall of agricultural exports, which fell by $ 1.01 billion, 38.4% of the total net decline, while its exports of transportation equipment, computer and electronics, and chemicals combined grew by $ 450 million. The four categories shared the same exchange rate but had drastically different performances. Hence, the figures cannot be explained by the RMB exchange rate. According to official Chinese trade data, the value of its soybean imports (predominantly from the US) during the Jan.-July period fell by 19.6% over a year ago, although the import quantity grew by 7.0%. The reason is apparently the sharp fall of soybeans prices in the world market. It can also be demonstrated by the similar pattern of US agricultural exports to the world, which fell by $ 12.09 billion over the first half of 2015, accounting for 28.9% of the total net export decline.

In conclusion, the primary factor affecting China-US bilateral trade performance is the trade structures and world commodities market, rather than the exchange rates between the RMB and the dollar. The two nations and business communities should focus on identifying the complementary sectors and products of the two countries and seeking a sustainable pattern of stable growth based on mutual benefit.