8月11日，中国人民银行宣布未来做市商向它提供的报价应基于前一日市场收盘价。与此同时，人民银行将人民币兑美元中间价下调1.9%。

这次贬值给全世界带来冲击。许多外国评论家担心中国人民银行让人民币贬值是为了提振中国的出口，从而引发新一轮货币战。

这种担心可以理解，但没有必要。就像中国人民银行副行长易纲所说：“我们无需靠人民币贬值来促进出口。”有许多理由可以相信这一点。首先，中国很清楚货币战争是搬起石头砸自己的脚。亚洲金融危机期间，中国经济状况更糟，但中国政府抵制住了人民币贬值的诱惑。虽然没有采取贬值手段，中国仍然毫发无损地渡过了危机。其次，中国正努力将增长模式从投资－出口驱动向消费驱动转变。中国仍有巨额贸易盈余，贸易盈余不断下降给经济带来的消极影响，可以而且应该由国内需求特别是国内消费需求的增加来抵消。第三，作为世界最大贸易国，中国在全球出口所占的份额已经超过12%，继续扩大这一份额很难不导致贸易条件的恶化。第四，由于中国在加工贸易和全球生产价值链中的特殊地位，很难说人民币贬值会对中国贸易盈余的增加有什么效果。最后，中国不仅是贸易国，也有巨额海外金融资产和负债，中国非金融公司的海外借款高达1万亿美元。人民币任何大幅度贬值都将相应地增加中国企业的人民币债务负担，从而导致大量破产和不良贷款急剧增加。因此，避免卷入竞争性贬值不仅是作为主要大国的中国的责任，也符合中国自己的利益。

在我看来，中国人民银行8月11日采取行动的背后有双重目的。一是放宽中国人民银行对人民币汇率的控制，以便让市场在人民币汇率的决定中发挥更大作用。二是缩小官方汇率与反映市场供求的汇率之间的差距，以便汇率机制改革更加顺利。世纪之交以来，美国和其他主要工业国一直敦促中国让市场来决定人民币的汇率机制。当中国朝这个方向努力，但最终结果是人民币贬值的时候，它们的抱怨合理吗？

出于种种原因，现在中国比任何时候都希望进行这样的改革。8月11日人民币的贬值，是中国姗姗来迟的汇率制度改革的一个重要里程碑。但我认为，由于事实上人民币贬值压力很大，如果中国人民银行不加干涉地由做市商决定人民币中间价，计划中的一次性汇率调整就可能变成崩盘，而这一前景不是中国人民银行希望见到的。结果，仅仅试水两天之后，中国人民银行就后退，并告诉市场人民币只贬值3%，不会更多。市场也认为如此。之后人民币汇率适度反弹，市场回归平静。

8月11日的插曲已经结束，但8月11日到13日人民币汇率的大幅下跌表明，人民币单向升值时代已经结束。未来，由于中国资本账户自由化和人民币国际化，人民币汇率将更为波动。由于中国经济增长持续疲软，中国人民银行很可能会进一步放宽货币政策。与此同时，美联储将逐步退出量化宽松。这样，在可预见的将来，人民币贬值的可能性要大过升值。

如何让市场决定人民币汇率的同时防止贬值失控，是对中国货币决策者的严峻挑战。对世界其他国家来说，如何在鼓励中国放松对人民币汇率管制的同时平静地看待人民币贬值，同样也是一个严峻挑战。希望双方都经得起考验。

On August 11, the People's Bank of China (PBOC) announced that in future the offer prices reported to it by market makers should be based on the closing parity rate of the market on the previous day. At the same time, the PBOC lowered the central parity rate by 1.9 per cent.

The depreciation sent a shockwave around the globe. Many foreign commentators feared that the PBOC has embarked on a course of devaluation to boost China's exports, which in turn would set off a new round of currency war.

This worry is understandable but unwarranted. As pointed out by the vice-governor of the PBOC, Yi Gang, “We do not need to devalue the RMB to promote exports.” There are many reasons to believe this is true. First, China knows well that currency wars are self-defeating. During the Asian Financial Crisis, China's economic situation was much worse, but China resisted the temptation to devalue the RMB. Even without resorting to devaluation, China was able to come out of the crisis unscathed. Second, China is very serious about shifting the growth mode from investment-export driven to domestic consumption driven. China is still running large trade surplus, the negative impact of a further narrowing in trade surplus on the economy can and should be offset by increase in domestic demand in general and domestic consumption in particular. Third, as the largest trade nation in the world, China's share of exports in global exports has already surpassed 12 per cent. It will be very difficult indeed for China to expand its share further without worsening its terms of trade greatly. Fourth, due to China's special position in processing trade and global value chain of production, it is difficult to assess how effective the devaluation will be in increasing China's trade surplus. Finally, China is not only a trading nation but also a nation with huge overseas financial assets and liabilities. Chinese nonfinancial corporations' foreign borrowing can be as high as 1 trillion USD. Any large devaluation will correspondingly increase the Chinese firms' debt burden in RMB terms, which will lead to a large number of bankruptcies and dramatic increase in nonperforming loans. Hence, to avoid getting involved in competitive devaluation is not only the responsibility of China as a major global power but also in its own self-interest.

In my view, the purpose behind the action taken on August 11 by the PBOC is twofold. First, to loosen PBOC's grip on the RMB exchange rate so as to allow the market to play a more important role in determining the exchange rate. Second, to narrow the gap between official exchange rate and the exchange rate implied by market demand and supply so as to make the reform of the exchange rate regime smoother. Since the turn of the century, the United States and other major industrial countries have been pushing China to allow the market to determine the RMB exchange-rate regime. When China made an effort towards that direction but ended up with RMB depreciation, it is legitimate for them to complain?

Now China is more willing than before to carry out such a reform for various reasons. The August 11 depreciation is an important landmark in China's long-overdue reform of its exchange-rate regime. However, I guess, due to the fact that the RMB depreciation pressure is too strong, if the PBOC let the market makers determine the central parity rate without intervention, the original planned one-off adjustment of the RMB exchange rate could morph into a rout, which is not a prospect the PBOC is ready to face. As a result, after testing the water just for two days, the PBOC retreated and told the market that the devaluation was just 3 percent and no more. Because the PBOC has enough ammunition to stabilize the exchange rate and the market also believes so, the exchange rate rebounded duly and calm returned to the market.

The August 11 episode has ended. However, the dramatic fall in the RMB exchange rate from August 11 to 13 August shows that the period of one-way appreciation of the RMB has ended. In the future, because of China's capital account liberalization and RMB internationalization, the RMB exchange rate will become more volatile. It is very likely that because growth of the Chinese economy will continue to be weak, the PBOC will have to loosen monetary policy further. At the same time, the US Fed will exit quantitative easing gradually. As a result, in the foreseeable future, the RMB is more likely to depreciate than to appreciate.

For the Chinese monetary authorities, how to allow the market to determine the RMB exchange rate while preventing the depreciation from sparking a rout is a serious challenge. For the rest of world, how to cheer China on to let go the RMB exchange rate while watching RMB depreciation in a quiet manner is an equally serious challenge. Hopefully, neither side will fail the tests.