What is behind global financial markets’ extreme moves since China’s decision to allow its currency to move to a managed float? One explanation is that investors increasingly fear that global disinflation is not a dragon that has been slain by muscular central bank measures, but a phoenix that is rising from the ashes.

自中国决定允许人民币迈向“有管理的浮动”以来，全球金融市场经历了极端波动，这背后的原因是什么？有一种解释是，投资者日益担心全球“通胀减速”(disinflation)并不是一条被强硬的央行措施手刃的巨龙，而是一只浴火重生的凤凰。

Certainly the direct impact of the renminbi fall on US and European inflation and economic activity — even if it extends to 10 per cent — is too small to justify the large falls in bond yields and inflation gauges. The renminbi’s weight in the trade-weighted dollar and euro is about 20 per cent and, as a rule of thumb, a 10 per cent rise in the trade-weighted dollar and euro takes about 0.5-0.6 per cent off inflation and real GDP growth over 18 months. So even if the renminbi is devalued by 10 per cent, the effect would be to cut US and European inflation and growth by only

当然，人民币下跌对美国、欧洲的通货膨胀以及经济活动（即便跌幅达10%）造成的直接影响太小，不足以解释后两者债券收益率和通胀指标的大幅下滑。人民币在贸易加权美元和欧元中的比重约为20%，一般来说，贸易加权美元和欧元每上涨10%，在18个月内可使通胀率和实际GDP增长率下降0.5%-0.6%。因此，在其他条件不变的情况下，即便人民币贬值10%，影响也不过是在一年里将美国和欧洲的通胀水平和经济增长拉低10至20个基点。

10 or 20 basis points over a year, other things being equal.

最近大宗商品价格下跌同样不会造成那么大的影响。没错，大宗商品进一步疲软也削弱了短期的通胀前景。但是，随着时间推移，基准效应会向前滚动，此类下跌将不再影响同比通胀数据。而且大宗商品价格下跌相当于为十国集团(G10)的生产者和消费者减税。因此，尽管大宗商品价格的新一轮下跌令人震惊，且短期影响肯定也很大，但很难看出这会直接导致长期债券收益率和远期通胀水平下滑。

The same is true of the fresh fall in commodity prices. Yes, further weakness in commodities also weakens the near-term inflation outlook. But such falls wash out of year-on-year inflation data over time as base effects roll forwards. And they amount to a tax cut for G10 producers and consumers. So although the renewed fall in commodity prices is striking, and its near-term effects undoubtedly significant, how it can directly justify a fall in long-term yields and inflation forwards is difficult to see.

然而，美国和欧洲的长期债券收益率和远期通胀水平一直在急剧下滑。自6月底以来，30年期美国国债收益率下跌了50个基点。该指标反映的是投资者对长期通胀和经济增长的预期。而这还是发生在2年期国债收益率——反映市场对官方利率动向的预期——几乎没变的情况下。

Nonetheless long-term bond yields and inflation forwards in the US and Europe have been falling quite dramatically. Since the end of June, 30-year US Treasury yields, which should reflect investors’ expectations for long-term inflation and economic growth, have fallen 50bp. And this in spite of the fact that two-year yields, which reflect expectations for the path of official interest rates, have barely changed.

有一种说法或许可以解释债券和通胀市场动向——即这是一种短期的“避险”举动，同时伴随着股市回调、夏季交易清淡，而共识性交易（做空债券、做空美国做多欧洲、做多通胀）遭受最大冲击。但是，如果原因是投资者日益担心当前的通胀减速压力是长期性的而非周期性的、而人民币走软只是一系列令人不安的因素中最新的一个呢？眼下还有其他迹象表明通胀减速因素仍然存在。

One possible explanation for the bond and inflation markets’ behaviour is that it is a short-term “risk-off” move, together with the correction in stock markets, in thin summer trading, with consensus trades (short bonds, short US against Europe, long inflation) suffering most. But what if the explanation is that investors are growing more fearful that disinflation pressures are secular rather than cyclical, with weakening in China’s currency just the latest in a series of unsettling factors? There have been other signals that disinflationary forces are still with us.

尽管失业率下滑，但美国和英国（市场预计它们会比其他国家先加息）的薪资水平增长仍然乏力。核心消费价格指数（剔除能源和食品）也仍然低于央行的政策目标，只是在缓慢上升。

Pay growth in the US and UK, where rate rises are expected before anywhere else, remains sluggish in spite of falling unemployment. Core consumer price inflation (excluding energy and food) also remains below central banks’ policy targets and is rising only slowly.

债券收益率的变化几乎完全是通胀预期下滑的结果。自从人民币汇率机制改变以来，美国和欧元区地区的5年远期通胀率（央行倾向于把这作为中期通胀预期的指标）自1月份以来的涨幅已经抹去了一半多。

The change in bond yields is almost entirely the result of falling inflation expectations. Since the change in the Chinese currency regime, in both the US and the euro area the five-year forward inflation rate (favoured by central bankers as an indicator of medium-term inflation expectations) has given up more than half its gains since January.

市场新出现的对通胀减速或通缩的担心很可能会在未来几个月加剧、而非减轻。大宗商品价格走低以及人民币贬值意味着，对市场短期通胀预期的调查更可能显示出下滑、而不是上升；而中期通胀走向将低于之前预期。

It is likely that in the coming months renewed fears of disinflation or deflation will increase rather than diminish. Weaker commodity prices and the renminbi devaluation mean surveys of inflation expectations are more likely to show a fall than rise near term; and the medium-term trajectory for inflation will be lower than previously thought.

果真如此的话，一场辩论将重新开启：央行是否有能力克服物价的结构性下滑因素，特别是全球化、技术变革以及人口结构变化，还有全球金融危机的后续效应。

If so we could be in for a revival of the debate about whether central banks have the ability to overcome structural downward forces on prices, notably globalisation, technological change and demographics, to which we can add the after-effects of a global financial crisis.

在经济出现周期性好转、特别是美国和英国失业率下滑的情况下，这场辩论已经处于中断状态。其中隐含的假设是，零利率、量化宽松、经济复苏结合起来，可以恢复通胀水平。

With the cyclical upswing, particularly the falls in US and UK unemployment, this debate has been in abeyance. The implicit assumption has been that the combination of zero interest rates, quantitative easing and economic recovery would bring about a revival in inflation.

但是，这种假设如今显然是存在疑问的。如果真是这样，任何加息决定都会很快成为一个政策性错误。

But this assumption is apparently being questioned. If that is the case, any decision to raise official interest rates could soon start to seem like a policy mistake.

对于投资者和政策制定者而言，事实将证明，对长期性通胀减速的担忧是很难扼杀的。