China’s central bank has flummoxed and rattled markets with its apparent shift of goalposts on the renminbi.

中国央行似乎改变了人民币汇率策略，令市场既困惑又惊慌。

Having spent tens of billions of dollars over recent months in a seemingly Sisyphean attempt to support the renminbi, it has twice this week stood aside while it weakened.

最近几个月，中国央行动用了数百亿美元资金，似乎徒劳地想支撑人民币汇率。然而，该行本周却两度在人民币走软时袖手旁观。

Plenty of domestic government agencies welcome the People’s Bank of China’s willingness to let the market drive down the renminbi against the US dollar. These include the commerce ministry, with its traditional concern for the country’s struggling exporters.

中国央行愿意放任市场推低人民币兑美元汇率，许多国内政府机构自然欢迎，比如一直担心国内出口企业困境的商务部。

But the blowback on the stock market has magnified the challenge confronting China’s regulator, which has been left struggling to stem the damage.

然而，人民币走软给股市造成的冲击，却加剧了中国股市监管机构面临的挑战，后者正在艰难地试图减小这种冲击。

Further afield, the weaker renminbi as measured against the dollar risks sparking beggar-thy-neighbour devaluations across the region.

从更大的范围来说，人民币兑美元汇率走软，可能会在亚太地区引发以邻为壑的贬值潮。

The PBoC has traditionally shied away from involvement in the country’s stock markets, which are the preserve of the embattled China Securities Regulatory Commission.

中国央行历来避免插手股市，因为那是由中国证监会(CSRC)专门负责的。后者如今已是焦头烂额。

“The PBoC doesn’t want to get its feet wet in the stock market because it is so chaotic and the rules keep changing so much,” Chen Long, China economist at Gavekal Dragonomics, says. “The PBoC is happy to stay away from it and let the CSRC play the role of clown.”

龙洲经讯(Gavekal Dragonomics)中国经济学家陈龙表示：“央行并不想管股市的事，因为股市太过混乱，规则又变来变去。央行乐于站在一边，让证监会去出丑。”

The CSRC has come under a barrage of criticism for its on-again, off-again support measures.

中国证监会已因其时有时无的托市措施而饱受批评。

In another reversal, the regulator yesterday confirmed that it would extend a ban on share sales by large shareholders that had been set to expire today.

昨日中国证监会证实将延长原本于今天到期的大股东减持禁令，再次彰显出其政策的反复无常。

But some analysts fear that the central bank may have failed to appreciate the strength of the feedback loop between its currency policy and China’s gyrating stock markets, which could force it to once again cushion the renminbi’s accelerating fall against the dollar.

不过，有些分析师担心，中国央行也许未能认清其汇率政策与波动不定的国内股市之间反馈回路的威力，这可能会迫使该行再次采取措施缓和人民币兑美元的加速下跌趋势。

“The wild market movement appears to be out of the authorities’ expectation,” Zhou Hao, an economist at Commerzbank, says.

德国商业银行(Commerzbank)经济学家周浩表示：“股市的剧烈波动似乎超出了当局的预期。”

He notes that there was “aggressive intervention” yesterday in the offshore market, where the renminbi generally trades at a discount to its onshore counterpart, driving the currency from Rmb6.76 against the dollar to Rmb6.70.

他指出，昨天离岸人民币市场存在“激进的干预行为”，将人民币汇率从1美元兑6.76元人民币推升至1美元兑6.70元人民币。通常，离岸人民币汇率会比在岸汇率低一些。

In China, the PBoC sets a daily renminbi-dollar midpoint around which the Chinese currency is allowed to rise or fall by no more than two per cent.

中国央行每日设定人民币汇率中间价，人民币汇率只能在中间价上下2%的区间内浮动。

“The [renminbi-dollar midpoint] over the past several days can be well justified,” Mr Chen says. “But it’s true that the PBoC has been much more tolerant of renminbi depreciation. It has been remarkably quiet.”

“过去几天（人民币兑美元汇率中间价）可能十分合理，”陈龙表示，“但央行的确对人民币贬值宽容得多了。央行一直非常平静。”

While this also appears to contradict the PBoC’s earlier desire — reiterated by officials including Premier Li Keqiang — for currency stability over a “currency war”, analysts including Mr Chen dismiss any inconsistency.

尽管这似乎有悖央行之前保持汇率稳定、避免“货币战争”的愿望——中国总理李克强等官员也重申过这一立场——但陈龙等分析师并不认同中国央行政策前后不一的说法。

Rather than shifting its goal of currency stability, analysts say the PBoC has changed the metrics for measuring that goal.

分析师表示，中国央行并非改变了保持汇率稳定的目标，而是改变了衡量这一目标的指标。

Shortly before the US Federal Reserve’s interest rate rise on December 17, China’s central bank emphasised that it would be carefully watching the renminbi’s movement against a basket of 13 currencies — the CFETS RMB index.

在12月17日美联储(Fed)加息前不久，中国央行曾强调会密切观察人民币对由13种货币组成的一篮子货币的汇率走向——中国外汇交易中心(CFETS)人民币汇率指数。

In contrast to the renminbi’s more than four per cent fall against the dollar since November 1, it has broadly tracked the larger basket.

自11月1日以来，人民币兑美元汇率累计跌幅超过4%。相比之下，人民币与一篮子货币的走向基本一致。

“Investors should focus more on the index, whereas now they are obsessed with the rate to the dollar,” Tao Wang, China economist at UBS, says.

“投资者应该对CFETS指数投入更多关注，但他们现在却执着于人民币兑美元汇率，”瑞银(UBS)中国经济学家汪涛表示。

The extent of that obsession was illustrated by yesterday’s sharp falls on China’s stock markets, triggering circuit-breakers that ended trading within half an hour of opening.

这种执着程度可以从昨天中国股市的暴跌中看出。昨日熔断机制再度触发，致使股市在开盘交易半小时内休市。

Last night the CSRC said it would suspend the mechanism.

昨天晚间，中国证监会表示将暂停熔断机制。

Among the institutions responsible for regulating China’s financial sector, the PBoC has traditionally been the staunchest defender of a strong renminbi. Even after the central bank shocked markets in August with a “one-off” devaluation of the renminbi, which it marked down by 1.9 per cent against the dollar, it argued that it was merely responding to calls from the IMF and its big trading partners for the currency to be more market-driven.

在负责监管中国金融业的机构中，中国央行传统上一直坚定维护强势人民币。即使是在2015年8月震惊市场的人民币“一次性”贬值、导致人民币兑美元汇率下跌1.9%后，中国央行也声称这只是在响应国际货币基金组织(IMF)和重要贸易伙伴对人民币应更加以市场为导向的呼声。

As the renminbi came under pressure in the devaluation’s wake, the PBoC sold down its foreign exchange reserves to keep it stable against the dollar.

在那次贬值后，人民币受到压力，中国央行于是抛售外汇储备，以保持人民币兑美元汇率稳定。

But the Fed’s December rate rise changed the PBoC’s calculus.

但美联储12月的加息改变了中国央行的想法。

“Why waste reserves defending a level that isn’t defensible?” says Mr Chen, who expects a “short-term equilibrium” of Rmb6.6 to Rmb6.7 against the dollar in the onshore market.

陈龙表示：“为何要浪费储备坚守一个根本守不住的防线呢？”他预计，在岸人民币兑美元的“短期均衡汇率”为1美元兑6.6到6.7元人民币。

Ms Wang, who has a year-end target of Rmb6.8 to the dollar, says: “The depreciation is well within our expectations.”

汪涛预测今年底人民币兑美元汇率为1美元兑6.8元人民币。她表示：“人民币贬值完全在我们的预期之内。”