In the seven years since it was elevated to the level of supposed guardian of global stability, the G20 grouping of large economies has struggled to make a noticeable impact.

自二十国集团(G20)地位被提升至人们期待的全球稳定守护者以来，已有七年。在这七年里，由最大经济体组成的G20却一直未能发挥显著影响。

In general, though they have paid lip service to global co-operation over macroeconomic policy, none of its members has been overly bothered about ignoring the views of the rest of the group. Each has generally gone its own way on fiscal, monetary and exchange rate policies.

总体来说，尽管G20嘴上说要促成全球在宏观政策方面的合作，但没有哪个成员国对无视其他成员国的看法太过意不去。各成员国基本上都一直在按照自己的想法实施财政、货币和汇率政策。

But at Friday’s meeting of G20 finance ministers in Shanghai, the stakes for failing to co-ordinate policy across the world are higher than for some time. With recent financial market turmoil and great uncertainty about Chinese economic prospects, a sense of unease has persisted since the turn of the year.

不过，在周五于上海召开的G20财长会议上，能不能在政策上实现全球协调一致，将比一段时间以来更加事关重大。考虑到近期金融市场的动荡以及中国经济前景面临的巨大不确定性，一种不安全感自开年以来一直挥之不去。

Although the global economy has continued to expand, the need for a general effort to prepare monetary and fiscal stimulus has become more pressing. And while it may be too much to hope that the G20 countries will finally all move together, they should at least satisfy themselves that their policies are consistent with the greater good.

尽管全球经济一直持续增长，共同努力筹备货币和财政刺激举措的必要性却已变得更加迫切。虽然或许不应指望G20国家终于能够全都步调一致，但他们至少应该确保其政策能够符合所有人更高的利益。

The International Monetary Fund and the Organisation for Economic Co-operation and Development have both warned that growth appears to have slowed late last year and early this, even before the recent turmoil in equity markets worldwide. The OECD says global growth is likely to be around the same in 2016 as in 2015, itself the weakest for five years.

早在最近的全球股市动荡之前，国际货币基金组织(IMF)和经合组织(OECD)就曾警告说，去年底和今年初，全球增长似乎已经放缓。经合组织表示，2016年全球增长可能会和2015年差不多，而2015年本身是这五年里增长最疲软的一年。

Moreover, with the advanced economies continuing to generate underlying fiscal surpluses and hence subtract from demand, only China of the big countries is running a public deficit.

此外，发达经济体仍在继续产生基本财政盈余、从而减少需求，大国中只有中国在维持公共财政赤字。

This is not the moment to take global expansion for granted and to focus on fiscal consolidation. Monetary policymakers — with the large and regrettable exception of the US Federal Reserve — have been trying to loosen policy, with both quantitative easing and negative interest rates.

眼下不是把全球增长视为理所当然、把重心放在财政整固上的时候。各国货币政策制定者一直在试图以量化宽松和负利率手段放宽货币政策——但遗憾的是，主角美联储(Fed)不在其中。

Their efforts would have more impact if they were financing a fiscal expansion rather than acting alone. As many observers have pointed out, economies with anaemic private demand and low long-term interest rates are ideally placed to undertake publicly financed investment in the hope of boosting short-term growth and medium-term productivity.

如果这些货币政策有扩张性财政政策配合，而不是在孤身作战，或许会起到更大作用。正如许多评论人士指出的，私人需求疲软、长期利率低迷的经济体，最适合用公共资金进行投资——这种做法有望在短期提振增长、在中期提高生产率。

The risk of monetary expansion without a fiscal counterpart is that it can lead to international tension, even if the motives of the central banks involved are honourable. Quantitative easing in both the eurozone and Japan was primarily aimed at loosening domestic monetary conditions but also, at least initially, pushed down their exchange rates. With the renminbi under downward pressure, another conflict could emerge over alleged competitive devaluations.

只实行货币扩张政策而不配合财政扩张政策，可能会导致国际上的紧张局面——即使央行是出于正当理由这样做。欧元区和日本的量化宽松举措，主要都是为了放松国内的货币环境，然而至少在一开始，此举也压低了本币汇率。在人民币面临下行压力之际，可能出现又一场围绕所谓竞争性贬值的冲突。

Such concerns are only amplified by doubt over how much control the People’s Bank of China, as opposed to other agencies and the Chinese Communist party, truly has over monetary policy.

人们对如下这个问题的疑问更加剧了上述关切：相对于其他同行和中国共产党，中国央行对货币政策到底有多大控制权？

At the very least, even if they cannot all move together, policymakers need to understand each other’s intent. Looser monetary policy — and fiscal stimulus even more so — need not be a zero-sum game if it generates higher growth and more trade rather than simply taking a larger share of global demand through a weaker currency.

退一万步说，就算各国政策制定者做不到步调一致，他们至少也需要正确理解彼此的意图。如果更宽松的货币政策能带来更高增长和更多贸易，而不只是通过货币贬值从全球需求中攫取更大份额，那么这种政策就未必非得是零和游戏——财政刺激更是如此。

The G20 is unlikely to emerge from this week’s meetings with a unified action plan. But its members should be aware that the moment when they are forced to move to bolster sagging growth has come noticeably closer over the past few months.

G20不太可能在本周的会议中拿出一份统一行动计划。不过其成员国应该认识到，过去几个月里，它们不得不采取措施支撑疲软增长的时刻已显著迫近。