人民幣對美元匯率上周突然下跌，震動全球股票市場，引起各國媒體強烈反響，包括新加坡元、韓國元、越南盾和馬來西亞林吉特在內的一批亞洲貨幣隨即下跌。隨着南非蘭德貶值，這場衝擊也漫延到非洲。《華爾街日報》8月17日評論稱，人民幣貶值嚇壞了中國的非洲夥伴。美國參議員羅伯特·凱西甚至敦促奧巴馬政府給中國貼上貨幣操縱國標籤。

但是，在8月17日布魯金斯學會的發言中，艾倫·格林斯潘作了更專業的評價，他贊成中國央行最近的行動，認為這是朝建立市場導向匯率機制所採取的積極步驟。

估值過高的人民幣終於接近其真正市場價值

採取最近這次行動前，中國人民銀行過去幾個月一直將人民幣對美元每日比價定在6.11，而離岸外匯市場實際匯率低於6.20，顯示官方比價明顯過高。8月11日，中國人民銀行基於前日約6.22的實際市場交易水平，將官定比價從前一日的6.1162調降到6.2298，貶值幅度為1.8%。當天市場上人民幣匯率降到6.3以下，這說明實際匯率應該更低。第二天，人民銀行再次基於實際市場價格，把人民幣比價定為6.3306，第三個交易日又降到6.4010，並迅速在接下來的五個交易日里將匯率穩定在6.3915－6.3975，直到8月20日，人民幣對美元累計下跌4.5%，或多或少反映了當前人民幣在市場上的水平。它同時也表明，由於市場基礎不充分，人民幣之前的匯率是過高的。

隨着人民幣對美元匯率在新的水平上穩定下來，下周全球股市和匯市很可能恢復正常。

最近的人民幣貶值，是匯率形成機制在完全市場化和政策性扭曲最小化方面取得重要進展的結果。這也是國際貨幣基金組織和美國政府一直以來要求中國做的。

問題在美元，而不是人民幣 

與美元的比價是人民幣匯率的基準，但它並不是人民幣貶值或升值的官方標準。官方度量標準，是人民幣對國際清算銀行設定的一攬子貨幣的實際有效匯率（REER）。近幾年裡，人民幣REER一直過高，已經難以持續下去。

主要貨幣的REER

          人民幣     美元     歐元      日元    巴西雷亞爾 馬來西亞林吉特

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

期間內變動幅度

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%

資料來源：國際清算銀行及相關統計

到2012年12月，從經常項目盈餘佔GDP比重和貿易盈餘占貿易總額比重判斷，人民幣匯率應該處在一個平衡區間內。但自那時起到上月為止，人民幣REER上升了19.6%，達到1994年1月國際清算銀行首次紀錄REER以來最高水平。相比之下，美元上升了18.8%，歐元、日元、巴西雷亞爾和馬來西亞林吉特匯率同期內全部大幅下跌。結果是，人民幣對美元升值0.7%，對歐元、日元、巴西雷亞爾、馬來西亞林吉特分別升值23.7%、61.2%、55.1%和30.0%。顯然，人民幣REER已經偏離均衡水平，需要由市場向下糾正。

經過近期下跌，人民幣只對美元出現貶值，但對其他主要貨幣仍相當堅挺。人民幣REER是基於若干主要貨幣，其中最大權重是歐元，接下來是美元和日元。讓人民幣REER緊跟美元REER是不可能的。人民幣對美元貶值更多是由於美元堅挺，而不是人民幣疲軟。

在全球貨幣市場上，匯率的起伏是常態。沒有人抱怨歐元下跌。歐元2008年兌換1.46美元，去年兌換1.30美元，目前在1.10美元上下浮動，高盛公司預計這一水平將維持到年底。日元對美元下跌得更厲害，從2010年的83日元跌到最近的接近120日元。對此同樣也沒有人抱怨。那麼，為什麼要對人民幣的貶值大驚小怪？

人民幣對美元下跌最根本的原因不在於人民幣本身，因為它的REER仍然非常高，而在於美元過於堅挺。美元對主要貨幣的名義匯率指數2014年1月只有77.1141，2015年7月達到91.6450，19個月里上升24.5%。顯然，人民幣不能追隨美元的匯率水平。

自從與黃金脫鉤以來，過去42年，美元已經表明有自己的漲跌周期。有意思的是，2009年3月到2010年10月的19個月里，美元下跌14.0%，而美國議員們並沒有發出抱怨。

可以預見，由於美聯儲是否加息仍懸而未決，美元未來幾個月將繼續堅挺，從而使人民幣對美元有更多貶值空間。考慮到中國經濟基本面，人民幣貶值將是有限的，到年底對美元降至6.50－6.60也是合理的。然而，由於美元已經充分堅挺，接下來的階段就是美元下跌。在這個階段，人民幣對美元將再度升至6.40、6.30甚至6.20。

匯率對中美貿易影響甚微 

過去八年中美雙邊貿易的增長曲線顯示，人民幣對美元比價與雙邊貿易並沒有很強的關聯性。

相反，據美國國際貿易委員會的官方貿易統計，人民幣對美元升值推動中國對美國的出口。2008年人民幣再次盯住美元的時候，中國對美國的出口增長緩慢（增幅只有5.1%，而全世界對美出口增長7.5%）。2010－2014年人民幣再次浮動並對美元升值，同期中國對美元的出口增速超過世界其他地區（57.5%對50.5%）。2015年上半年，人民幣和美元同樣堅挺，中國對美國的出口仍然增長5.9%，而世界其他地區下降了3.4%。

至於美國對中國的出口，過去18個月里增長勢頭迅速減弱。2014年，美國對全球出口增長2.7%，對華出口只增長1.6%。2015年上半年，美國對華出口下降4.5%，與對世界其他地方的出口下降基本同步（5.2%）。對華出口下降的原因是可尋的，在很大程度上，是農業出口急劇減少10.1億美元，凈下降38.4%，而運輸設備、計算機和電子產品、化學品的出口增長4.5億美元。這四個領域採用同樣的匯率，卻有截然不同的表現。因此，這些數字無法用人民幣匯率來解釋。根據中國官方貿易數據，今年1月到7月，中國大豆進口（主要來自美國）按價值計算比去年同期減少19.6%，儘管進口量增加了7.0%。其原因很明顯，是世界市場上大豆價格出現大幅下跌。美國對全球的農業出口也顯示出同樣狀況，在2015年上半年減少120.9億美元，佔總凈出口下降的28.9%。

總之，影響中美雙邊貿易表現的主要因素是貿易結構和全球商品市場，而不是人民幣對美元匯率。兩國和兩國經濟界應該把關注點放在認清兩國的互補領域和產品上，尋求在互利基礎上可持續的穩定增長。

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.