哈佛大学经济学教授Robert J. Barro近日发文称，自从联邦基金利率在20世纪80年代初达到22%的峰值以来，美国的通货膨胀率一直保持在较低且稳定的水平，这使得许多人相信，仅仅是再次加息的威胁就能控制通货膨胀。但没有人真正知道为什么通胀会被抑制这么久。
One of the remarkable features of post-war economic history has been the taming of inflation in the United States and many other countries since the mid-1980s. Before then, the US inflation rate (based on the deflator for personal consumption expenditures) averaged 6.6% per year during索道发展股票牛叉诊股 the 1970s, and exceeded 10% in 1979-1980.
20世纪70年代初期和中期，美国总统理查德•尼克松(Richard Nixon)和杰拉尔德•福特(Gerald Ford)试图通过对价格控制和告诫的错误结合，以及适度的货币紧缩来遏制通胀。但随后，美国总统吉米•卡特(Jimmy Carter)在最初维持这种做法后，任命保罗•沃尔克(Paul Volcker)为美联储主席。在沃尔克的领导下，美联储很快开始将短期名义利率提高到任何可能降低通胀的水平。
In the early- and mid-1970s, Presidents Richard Nixon and Gerald Ford tried to curb inflation with a misguided combination of price controls and exhortation, along with moderate monetary restraint. But then came President Jimmy Carter, who, after initially maintaining this approach, appointed Paul Volcker to chair the US Federal Reserve in August 1979. Under Volcker, the Fed soon began to raise short-term nominal interest rates to whatever level it would take to bring down inflation.
Volcker, backed by President Ronald Reagan after January 1981, stuck with this approach, despite intense political opposition, and that July the federal funds rate peaked at 22%. The policy worked: annual inflation fell sharply to an average of just 3.4% from 1983 to 1989. The Fed had satisfied in extreme form what later became known as the Taylor Principle (or, more appropriately, the Volcker Principle), whereby the federal funds rate increases by more than the rise in the inflation rate.
Since then, the Fed has guided monetary policy primarily through control over short-term nominal interest rates, especially the federal funds rate. When its power over short-term borrowing costs was compromised following the 2008 financial crisis – because the federal funds rate approached its zero lower bound – the Fed supplemented its main policy instrument with forward guidance and quantitative easing (QE).
Judging by the US inflation rate over past decades, the Fed’s monetary policy has worked brilliantly. Annual inflation has averaged only 1.5% per year since 2010, slightly below the Fed’s oft-expressed target of 2%, and has been strikingly stable. And yet, the question is how this was achieved. Did inflation remain subdued because everyone believed that anything significantly above the 1.5-2% range would trigger a sharp hike in the federal funds rate?
有大量的研究是关于联邦基金利率的变化如何影响经济的。例如，中村惠美(Emi Nakamura)和乔恩•斯坦森(Jon Steinsson) 2018年在《经济学季刊》(Quarterly Journal of Economics)上发表的一篇论文表示，紧缩性货币冲击，以及联邦基金利率的意外上升，会在3至5年内推高美国国债收益率，其峰值效应为两年。(扩张性冲击的结果是对称的。)这些影响大多适用于实际利率，并体现在指数债券和传统国债中。收缩性冲击对预期通胀率的影响为负，但规模适中，仅在3-5年后才开始显著显现。
There is a large body of research into how changes in the federal funds rate influence the economy. A 2018 paper by Emi Nakamura and Jn Steinsson in the Quarterly Journal of Economics, for example, finds that a contractionary monetary shock – an unanticipated rise in the federal funds rate – raises yields on Treasury securities over a 3-5-year horizon, with a peak effect at two years. (Results for expansionary shocks are symmetric.) Most of these effects apply to real interest rates, and show up in indexed bonds as well as conventional Treasuries. The effect of a contractionary shock on the prospective inflation rate is negative but moderate in size, and sets in significantly only after 3-5 years.
Although unexpected increases in the federal funds rate are conventionally labeled as contractionary, Nakamura and Steinsson find that “forecasts about output growth” actually rise for the year following an unexpected rate hike. That is, a rate increase predicts higher growth, and a decrease predicts lowergrowth. This pattern likely occurs because the Fed typically raises interest rates when it gets information that the economy is stronger than expected, and it cuts rates when it suspects that the economy is weaker than it previously thought.
The same paper also finds that an unanticipated rise in the federal funds rate is bad for the stock market (and vice versa), which accords with the deeply held views of many financial commentators, not to mention US President Donald Trump. The authors estimate that an unanticipated rate cut of 50 basis points raises the S&P 500 stock-market index by about 5%, even though projected real GDP growth declines. The likely reason is the decrease in expected real returns on competing financial instruments, such as Treasury bonds, over the next 3-5 years. This discount-rate effect overshadows the negative influence on stock prices from lower expected future real earnings.
But, again, the puzzle is how the Fed can keep inflation steady at 1.5‑2% per year by relying on a policy tool that seems to have only weak and delayed effects. Presumably, if inflation were to rise substantially above the 1.5-2% range, the Fed would initiate the type of dramatic increases in short-term nominal interest rates that Volcker carried out in the early 1980s, and these changes would have major and rapid negative effects on inflation. Similarly, if inflation were to fall well below target, perhaps becoming negative, the Fed would sharply cut rates – or, after hitting the zero-lower bound, use alternative expansionary policies – and this would have major and ra用kd指标做股票pid positive effects on inflation.
According to this view, the credible threat of extreme responses from the Fed has meant that it do股票5日线附近es not actually have to repeat the Volcker-era policy. Rate changes since that time have had modest associations with inflation, but the hypothetical possibility of much sharper changes has remained powerful.
Frankly, I am unhappy with this explanation. It is like saying that the inflation rate is subdued because it just is. And, no doubt, a key factor is that actual and expected inflation have both been low – the two are intimately connected twins. But this suggests that the monetary policy behind today’s low and stable actual and expected inflation will keep working until, suddenly, it doesn’t.
作者：Robert J. Barro
Robert J. Barro是哈佛大学经济学教授，美国企业研究所访问学者。他是《宗教财富：信仰和归属的政治经济学》的合著者（与Rachel M. McCleary合著）。
Robert J. Barro is Professor of Economics at Harvard and a visiting scholar at the American Enterprise Institute. He is co-author (with Rachel M. McCleary) of The Wealth of Religions: The Political Economy of Believing and Belonging.（完）
纽约联储 | 美联储如何影响境内外的美元货币市场利率
美联储 | 半年度货币政策报告：将采取适当措施来维持经济扩张
PIMCO | 从长期与短期角度：理解当前利率环境