2015年8月11日，中國人民銀行將美元對人民幣匯率的日常中間價提高了1.9%，從而導致人民幣對美元有效貶值1.8%，創下2005年7月人民銀行決定人民幣不再盯住美元以來的最大單日貶值紀錄。與此同時，中國人民銀行還宣布，即日起人民幣對美元的每日固定匯率將參考上一交易日的收盤價，以及外匯市場的供求狀況和全球主要貨幣的走勢。簡言之，中國央行開始讓人民幣匯率更多地由市場決定，而近期市場恰恰認為人民幣應該下跌。

研究中國問題的人士和主流媒體對此展開了熱烈討論：到底發生了什麼事？為什麼在這個時候發生？北京是通過貨幣競爭性貶值扶持萎靡不振的出口部門，還是期待人民幣被納入國際貨幣基金組織（IMF）特別提款權（SDR）而開始推進匯率自由化？

自由下滑

人民幣這回一次性貶值的主要催化劑，很可能是IMF此前一周發表的一份聲明。IMF認為，由於人民幣的重要基本指標仍然落後於世界其他主要貨幣，它可能推遲對人民幣納入特別提款權的評估。為此，中國人民銀行抓緊推行計劃中的人民幣匯率改革，而這次改革的基礎在兩個星期之前就已經備妥。就在7月24日星期五，中國國務院宣布將進一步擴大人民幣匯率的雙向浮動範圍。可以肯定的是，推出匯率改革也是中國人民銀行政治上的考慮，因為它最可能的結果是導致人民幣匯率下跌，這將支持經濟的增長。7月份，中國商品出口額按美元計算比去年同期下降了8.3%，顯示凈出口不再像2015年上半年那樣，能夠為國內生產總值的增長提供支持。

8月11日的一次性貶值，只是讓人民幣每日固定匯率更加市場化的第一步。過去幾個月里，人民幣對美元即期匯率一直趨向於接近人民幣交易區間的弱勢端，與此同時，中國人民銀行一直保持每日固定匯率不變。這導致人民幣在過去一年裡對其他貨幣升值約10%-15%。

當然，對於人民幣來說，即使貶值3%也算是大動作。今年人民幣最大波動幅度是0.16%，這與其他貨幣相比簡直是小巫見大巫。過去一年，歐元對美元貶值18%，日元對美元貶值22%。而且，人民幣過去18個月里幾乎對所有貨幣都在升值。到目前為止，它依然對歐元升值約20%，對日元升值15%，對韓元升值10%。

那麼，現在是什麼情況呢？8月12日人民幣又貶值了1.6%，這可能預示着，在中國人民銀行的引導下，人民幣匯率正形成一種混合的市場導向模式。12日，由於市場強烈預期人民幣會進一步貶值，人民幣對美元匯率出現下跌，但有報道稱，在交易最後時段中國人民銀行進行了干預，它指示國有銀行拋出美元，結果人民幣對美元匯率在交易最後幾分鐘上漲了大約1%，從而使周一（8月10日）以來的貶值幅度縮小到2.8%。

就市場而言，人民幣面臨的風險是出現自我完成式螺旋貶值。由於經濟增速減緩、資本流出加速以及受到通縮壓力，如今市場情緒已經達到負面。而政府在股市上救市失策，也沒有激發人們的信心。所以，中國人民銀行不太可能把人民幣完全交給市場。中國官員已經表示，人民幣與經濟基本面已經更趨一致。這暗示人民幣對美元繼續貶值的程度將是有限的。北京的真正目的到底是什麼，接下來的幾個星期將成為重要的指示器。如果是大幅度貶值，那麼出口會得到刺激。如果是中等幅度貶值，那麼人民幣不僅對美元，而且對一攬子貨幣的比價都會得到修正。

當心你的期望

長期以來，中國的國際貿易夥伴一直在勸說北京讓人民幣匯率自由浮動。全球金融危機發生後，這一呼聲更為強烈。美國議員們估計，中國一直在人為壓低人民幣匯率，以便使出口品在全球保持廉價。為此，他們預期人民幣在實現自由浮動後會對美元升值，而美國則恢復出口競爭力。對匯率操縱問題，華盛頓一直在進行辯論，但現在辯論比過去少了許多。IMF曾經表示，人民幣已經不存在估值過低問題。由於貿易數據疲軟，此刻讓人民幣更自由地浮動，可能對中國有利，但卻讓美國不舒服，因為這樣一來美聯儲9月份的加息預期就需要重新考慮。

北京會限制人民幣貶值幅度的另一個原因是，如果貶值速度太快、幅度太大，那就會進一步加劇中國與美國及其他貿易夥伴的緊張關係。北京沒有必要在習近平主席將要會見奧巴馬總統之前一個月，為美中雙邊議程再添加一個有爭議的議題。另外，儘管IMF歡迎中國人民銀行決定讓人民幣匯率自由浮動，並暗示它將更積極地考慮將人民幣納入特別提款權，但美國的議員們現在又把匯率操縱問題擺上檯面，並聲稱由於匯率操縱，人民幣沒有資格被納入特別提款權。因此，如果人民幣持續貶值，奧巴馬政府要想支持人民幣加入特別提款權就會面臨政治困難。

接下來的幾個星期十分關鍵。最大的可能是，北京所選擇的時機，是要趕在9月美中峰會到來之前，尤其是11月IMF作出決定前，讓人民幣匯率找到自己的底部。中國人民銀行下個月要維持微妙的平衡，要顯示出它允許人民幣匯率更加自由地浮動，而不是朝某個方向給人民幣施壓。

On August 11th, 2015, the People's Bank of China (PBoC), lifted the daily fixing rate for the USD-CNY exchange rate by 1.9%, leading to an effective 1.8% RMB devaluation, the biggest one day move since July 2005, when the PBoC de-pegged the RMB from the US dollar. At the same time, the PBoC also announced that from now on, the daily fixing rate for the RMB-USD will be made with a reference to the previous day's closing rate, and by taking into account FX market supply-demand and major global currency movements. Put simply, the PBoC moved to make the Chinese currency more market-determined, and right now the market determines that it should be weaker.

Debate in China-watching circles and the mainstream media has been heated: What just happened and why did it happen now? Is Beijing engaging in competitive devaluation aimed at boosting its ailing export sector or is it moving decidedly forward with currency liberalization, as it hopes to see the RMB included in the IMF's special drawing rights (SDR)?

Free falling

The main catalyst for the one-off depreciation was most probably the IMF statement the previous week, when the IMF concluded that the RMB trails its global counterparts in major benchmarks and suggested that review of the RMB's inclusion in the Special Drawing Rights (SDR) mechanism could be delayed. This prompted the PBoC to push forward planned reforms of the currency. The groundwork for such reform was already laid two weeks prior, when on Friday, July 24, the State Council announced its intention to further expand the two-way floating range of the exchange rate. To be sure, it was also politically expedient for the PBoC to launch the reform of the exchange rate when the most likely outcome—a weaker currency—could also support growth. Merchandise exports slumped on a US–dollar basis by 8.3% year on year in July, suggesting that net exports can no longer offer much support to GDP expansion going forward as they did in the first half of 2015.

The one-off devaluation on August 11 was therefore a first step in aligning the daily fixing more closely with the market. The CNY-USD spot exchange rates have gravitated to the weak end of the RMB's trading band for several months while the PBoC kept the daily fixing rates steady. This has led the RMB to rise against other currencies, by an estimated 10%-15% over the past year.

Indeed, even though a 3% depreciation is an enormous move for the RMB—its largest move this year has been 0.16%—it pales in comparison with other currencies: Over the past year, the euro has fallen by 18% against the US dollar while the Japanese yen has dropped by 22%. Moreover, the RMB has appreciated markedly against almost every currency over the last 18 months: it is still up around 20% against the Euro, 15% against the Yen and 10% against the South Korean Won.

So what now? The 1.6% depreciation on August 12 is probably a taste of things to come: a hybrid model of a market-oriented exchange rate, steered in the right direction by the PBoC. During the course of the day, the RMB fell against the USD given strong market expectations of further depreciation. But the PBoC reportedly intervened in the final minutes of trading, instructing state-owned banks to sell dollars on its behalf. As a result, the RMB gained roughly 1% against the USD in the last few minutes of trading, bringing it down 2.8% since Monday.

Left to the market's devices, the RMB risks going down a self-fulfilling depreciation spiral: Market sentiment is already negative due to economic slowdown, rising capital outflows and deflationary pressure. And the government mishandling the stock market bailout hasn't inspired confidence either. So the PBoC is unlikely to leave the RMB completely to the market's devices. Chinese officials have already indicated that the currency is now more aligned with economic fundamentals, suggesting that a further weakening of the RMB against the USD will be limited. The next few weeks will be important indicators of what Beijing is truly aiming for: A deep depreciation that will boost exports, or a modest devaluation that will correct itself as the RMB moves against a basket of currencies, rather than against the US dollar alone.

Careful what you wish for

China's international trading partners have long lobbied Beijing to let the currency float freely. These calls were loudest after the global financial crisis, when US senators estimated that China was keeping the RMB artificially low in order to make its exports cheaper globally. As such, they hoped that by letting the RMB float freely, it would appreciate against the USD and restore US export competitiveness. While the currency manipulation debate still surfaces in Washington from time to time, it is now more muted than in the past. And the IMF has already said that the RMB is no longer undervalued. Letting the RMB float more freely now, is perhaps convenient for China in light of its weak trade data, but potentially very inconvenient for the US that might need to rethink the Fed's expected rate hike in September.

This is another reason for Beijing to limit the extent of RMB depreciation: A rapid and significant weakening would further exacerbate tensions with the United States and other trading partners. Beijing does not need another controversial item on the bilateral US-China agenda, one month before President Xi is planned to meet with President Obama. Furthermore, even though the IMF has welcomed the PBoC's decision to free the currency and has suggested that it viewed SDR inclusion more favourably, US senators are now raising the currency manipulation flag once again, arguing that this disqualifies the RMB from SDR inclusion. A further weakening of the RMB would make it politically difficult for the Obama Administration to support the RMB's inclusion in the SDR.

The next few weeks will therefore be key. Most probably, Beijing timed the move to allow the RMB time to find its feet before the September summit, and more importantly, before the IMF review in November. The PBoC has a delicate balancing act over the next month: It must show that it is allowing the RMB to float more freely, without nudging it too forcefully in the right direction.