The coming turn in US interest rates may be the most telegraphed in many cycles. Yet for all Janet Yellen’s strivings at clarity, the US outlook remains clouded by poor visibility. Last week Ms Yellen said the Federal Reserve was still likely to raise interest rates this year — possibly in September — in spite of the sharp slowdown in first-quarter US growth. For one reason or another, including a series of harsh winters, growth in the first three months of the year has tended to underperform the rest of it, often heavily so. The US economy shrank by an annualised 2.9 per cent in the first quarter of 2014 only to rebound in the next three. Hopefully this year’s anaemic 0.2 per cent first quarter expansion will be equally misleading.
美国利率即将到来的转向或许将是多个利率周期以来媒体报道最多的一次。然而，尽管美联储(Fed)主席珍妮特•耶伦(Janet Yellen)极力保持透明，美国的利率前景依然疑云密布、难以看清。耶伦上周表示，尽管今年首季度美国经济增长大幅放缓，美联储仍有较大可能在今年加息——可能会在9月份。由于种种原因，其中包括连续几年都遭遇严冬，一年中头三个月的经济表现往往弱于、而且是远弱于余下几个月。2014年首季度美国经济以年率计萎缩了2.9%，结果在接下来3个季度里实现了反弹。运气好的话，今年首季度堪称疲弱的0.2%的增长率有望和2014年首季度一样具有误导性。

It would, however, be rash to make assumptions. It is quite possible 2015 will end as it began with US interest rates still on zero. As Ms Yellen put it: “Based on many years of making economic projections, I can assure you that any specific projection I write down will turn out to be wrong, perhaps markedly so.”
但现在就做出假设的话，恐怕过于轻率。很有可能到2015年结束的时候，美国的利率仍和年初一样为零。就如耶伦所说：“根据多年从事经济预测的经验，我可以向你们保证，我写下的任何具体预测都会被证明是错误的，或许还错得很离谱。”
Of course, there is a chance her expectations will be wrong on the upside. The Fed is forecasting US growth of 2.5 per cent for the next two years, which is only marginally above the tepid rates achieved since the start of the recovery, which is now about to enter its seventh year. Should unemployment fall to 5 per cent by the end of 2015, wage growth may finally start to pick up, in which case the Fed will probably need to remove the punch bowl. The balance of risk is skewed the other way, however. After years of virtually no income growth, Main Street is unprepared for positive shocks. It is, for instance, striking that that the US consumer has opted to pocket the recent gains from lower petrol prices rather than boost spending. The same applies to corporate investment, which remains disappointingly weak. The US economy’s key growth drivers each seem to be waiting for the other to move first. Investors are reluctant to invest and consumers are hesitant to spend. What will it take to stoke their animal spirits?
诚然，耶伦有可能低估了美国经济的上行力度。美联储目前对未来两年美国经济增长率的预测为2.5%，仅略高于复苏开始以来取得的不温不火的增长率，而复苏已即将步入第7个年头。如果到2015年末时失业率降至5%，我们可能会终于迎来薪资增长率的上扬，果真如此的话，美联储很可能需要取消刺激。然而，风险的天平正向另一端倾斜。在多年来收入增长基本为零的情况下，美国普通民众并没有做好应对正面冲击的准备。比如，人们惊讶地看到，美国消费者选择将近期油价走低给他们带来的收益放入囊中、而不是用来扩大支出。美国企业的投资状况也同样如此，依然低迷得令人失望。美国经济的每一个关键增长引擎似乎都在等待别的引擎率先发力。投资者不愿投资，消费者也不愿消费。需要什么才能激起他们的动物精神呢？
Ms Yellen’s candour on the limits of what monetary policy can do is also striking. The Fed has kept its pedal to the floor for seven straight years. Yet US growth since the collapse of Lehman Brothers in 2008 has consistently undershot previous recoveries. According to HSBC, average US growth in the seven years from the previous peak was 3.5 per cent after 1981, 3.1 per cent after 1990, 2.1 per cent after 2000 and 1.1 per cent since 2007.
耶伦对货币政策效果局限性的直言不讳同样令人惊讶。美联储已连续7年在“踩地板油”。不过，自雷曼兄弟(Lehman Brothers) 2008年破产以来，美国的增长率始终低于之前的数次复苏。汇丰(HSBC)数据显示，1981年增长率见顶后的7年里，美国的平均增长率为3.5%；1990年后的7年里为3.1%，2000年后的7年里为2.1%，而2007年以来的平均增长率为1.1%。