加息简史
ECONOMISTS and investors are not only worried about when the Federal Reserve will start to push up interest rates. Just as important is the scale and length of the tightening cycle—how much the Fed will need to tighten policy, and how long it will take to do so. There have been 12 American tightening cycles since 1955, and they have lasted just under two years on average. In five of the past seven instances, however, the Fed has relented in a year or less, largely because inflation has been relatively subdued in recent decades.
经济学家和投资者所担心的不仅仅是美联储开始推高利率的时机，同样重要的还有收紧周期的幅度和长度，即美联储需要将政策收紧到何种程度以及这种收紧会持续多长的时间。自1995年以来，美国总共有12个收紧周期，它们的平均持续时间刚刚不到2两年。然而，在过去7个周期的5个中，美联储态度仁慈的时间只有1年左右。这主要是因为通胀在近十年中一直是相对温和的。
The inflationary periods of the 1970s and early 1980s saw the biggest increases in interest rates; that helped push the mean increase over the 12 cycles to five percentage points. But the median change may be a better guide to the coming cycle; it stands at just over three percentage points.
上世纪70年代和80年代早期的通胀时期见证了最大幅度的加息；这曾经为将12个周期的平均加息幅度达到5个百分点做出了贡献。但是，对于即将到来的周期，变动的中位数可能是一个更好的指南；它刚刚超过3个百分点。
Central banks tend to push up rates when the economy is growing rapidly and inflationary pressures are emerging. If they overdo it, the economy may tip into recession. On average, a recession has followed about three years after the Fed's first hike. Yet that is partly because recessions are a regular occurrence. And tightening does not lead inevitably to a downturn: in 1983 and again in 1994 there was a gap of seven years between when the Fed started raising and the onset of the next recession.
央行往往会在经济快速增长和通胀压力开始显现的时候推高利率。如果他们做过了头，经济体可能会陷入衰退。平均而言，衰退都是在美联储首次加息过了大约三年后到来。不过，这部分是因为衰退是一种常态。同时，收缩并不是不可避免地带衰退：先是在1983年，而后是在1993年，在美联储开始加息到下一次衰退爆发之间都曾经有过7年的间隔。
Nor are higher rates necessarily bad news for equities. In nine of the 12 most recent cycles, the stockmarket has risen in the year following the first rate increase. Since the Fed tends to tighten when the economy is booming, profits are usually rising. In contrast, Treasury-bond yields rose in the first year of the cycle on all but one occasion.
加息之于股市也不必然就是坏消息。在最近12个周期的9个周期中，股市在首次加息后的那一年上涨了。由于美联储往往会在经济繁荣时开始收紧，所以，利润通常都处于上涨之中。与之相比，国债收益率只有一次是在收缩周期的第一年是上涨的。
A pertinent example might be the cycle that began in 1994. The Fed had kept rates low for a long time in order to help the financial sector, which was still recovering from the savings-and-loan crisis of the late 1980s. When it finally did begin to raise rates, the pace of tightening seemed to catch many investors by surprise, particularly those investing in mortgage-backed bonds. Askin Capital, a hedge-fund manager, went bust as a result.
一个适当的例子可能是始于1994年的那个周期。当时，为了帮助仍处于从上世纪80年代末期的存贷危机中复苏的金融部门，美联储曾经把利率维持在低位很长一段时间。当它最终开始加息时，收缩的步伐似乎曾让许多投资者措手不及，尤其是投资于抵押担保债券的投资者。结果，对冲基金公司——阿斯肯资本破产了。
Those who worry that the Fed might be moving too quickly point to policy mistakes elsewhere. As the Fed's chairman herself, Janet Yellen, remarked in March, “The experience of Japan over the past 20 years, and Sweden more recently, demonstrates that a tightening of policy when the equilibrium real rate remains low can result in appreciable economic costs, delaying the attainment of a central bank's price-stability objective.”
担心美联储可能动作过快的人所指的是其他国家的政策失误。作为美联储主席，珍妮特·耶伦曾在今年3月表示，“日本在过去20年和瑞典在最近这些年中的经历表明，“均衡实际利率处于低位时的政策收缩可能造成可观经济代价，延缓央行之于稳定物价目标的达成。”
Japan was the first country to reduce rates to zero (hitting the “zero lower bound” in the jargon) and the first to struggle with deflationary pressures and an ageing population. In August 2000 the Bank of Japan raised rates from zero even though prices were still falling; a recession started two months later. A second attempt at raising rates, in 2006, also had to be reversed two years later.
日本是第一个将利率降至0（用专业术语来说就是触及“零利率下限”）的国家，而且是第一个遭遇通缩压力和人口老龄化问题的国家。2000年8月，日本银行甚至在物价仍在下跌的情况下将利率提离了零；两个月后，一场衰退开始了。2006年的第二次加息尝试也不得不在两年后被反转。
Similar problems have bedevilled central banks that have attempted to raise rates in the wake of the financial crisis of 2007-08. The European Central Bank pushed up interest rates in 2008 and again, twice, in 2011, as the euro-zone debt crisis was unfolding. Sweden's Riksbank went even further, pushing rates from 0.25% to 2% in 2010-11 in response to a surge in inflation; by late 2011 the bank had to change course and Sweden now has negative interest rates.
同样的问题也在困扰着曾2007-08年金融危机后尝试加息的那些央行。欧洲央行曾在2000年推高了利率，之后，又在欧元危机渐次展开的2011年再次加息。为应对一次通胀飙升，瑞典央行甚至走得更远，在2010-11年间将利率从0.25%推高到了2%；到2011年晚些时候，瑞典央行不得不逆转了这一进程。如今，瑞典的利率是负的。
The sluggish nature of the recovery in the rich world since the crisis, and the high levels of debt that remain, explain why it has been so difficult for central banks to return to a “normal” level of interest rates. In the past, many central banks were usually raising rates at the same time. But any country that tightens policy at the moment will stand out from the crowd. Foreign capital may drive its currency higher, as investors take advantage of more attractive yields. That will act as a further tightening of policy, since a higher exchange rate reduces the price of imports, and so adds to deflationary pressures. That suggests this cycle, whenever it begins, will be shorter and less steep than in the past.
富裕世界自危机以来的复苏的疲软性以及目前仍处于高位债务水平，解释了央行为什么难以让利率回归正常水平的原因。过去，许多央行一般都是在同一时间加息。但是，凡是在这个时候收紧政策的国家都不会从众多国家中脱颖而出。由于投资者之于更具吸引力的收益率的充分利用，外国资本可能进一步推高其货币。这将发挥一种进一步收缩政策的作用，因为较高的汇率降低了进口商品的价格，因而也就加大了通缩的压力。这表明，这次的周期，不管从何时开始，会比以前的周期更短，并且少了一些陡峭。