美國股市在本周二表現出色，標準普爾500指數上漲了2.39%，但這并未打消華爾街對一場若隱若現的衰退的恐懼情緒。

盡管大部分經濟學家認為衰退不會在今年到來，但做出這種預測的經濟學家正在增加。如果真的出現衰退，分析家擔心它會成為史上持續最久的一次。匯豐證券首席美國經濟學家凱文?洛根周二對彭博新聞社表示：“如果發生衰退，嚴重性恐怕不及1990年和2001年那兩次，但長度恐怕更甚，因為利率不再能像以往一樣大幅降低了。”

原因在于，與過去不同，美聯儲不再擁有降低利率的空間。經濟學家大衛?貝克沃思最近在《金融時報》撰文解釋稱：

這個問題的真正原因在于美聯儲堅持低通脹策略。就像卡車司機會控制速度一樣，采用低通脹的策略可以防止經濟增速過快。一般來說，這是好事，但有時也可能適得其反。卡車司機有時也需要加速來彌補堵車浪費的時間。與之類似，經濟有時也需要加速，才能在一場衰退后發揮全部潛力。如果一直限制速度，就不可能實現這一點。

貝克沃思認為，美聯儲應當拋棄通脹目標，設立一個名義增長目標，這樣就能在低增長階段（正如我們正在經歷的這段時期）容忍較高的通脹率，后者將被高增長階段較低的通脹率所彌補。

并不是所有人都認同這種設立增長目標就能解決全部問題的論點。前財政部長拉里?薩默斯就沒有全盤支持貝克沃思的觀點，而是強調如今的低通脹環境給世界各國的政府都發出了信號，他們應該加大投入，刺激當前疲軟的需求。（財富中文網）

譯者：嚴匡正

審校：任文科

U.S. stock markets had a Super Tuesday, with the S&P 500 gaining 2.39%, but the latest moves haven’t quieted Wall Street fears of a coming recession.

Though most economists don’t see a recession coming this year, the number that do are on the rise. If and when it does come, analysts are starting to worry that the recession will be longer than most. “If a recession were to occur, it might be shallow but somewhat more extended than the 1990 and 2001 episodes since interest rates can’t be lowered as much,” said Kevin Logan, chief U.S. economist for HSBC Securities, to Bloomberg News on Tuesday.

The reason? The Federal Reserve doesn’t have nearly the room it is used to having, in terms of the ability to lower interest rates, as it usually does. Economist David Beckworth recently explained the problem in an essay for the Financial Times:

The real reason for this [problem] is the Fed’s firm commitment to low inflation. Like a governor placed on a truck’s engine to control its speed, a commitment to low inflation helps prevent the economy from growing too fast. Normally, this is a good thing. But sometimes it can backfire. A truck driver may need to temporarily go faster to make up for lost time after being stuck in traffic. Similarly, an economy may need to temporarily speed up to get back to its full potential after a recession. Neither can happen with a rigid adherence to the speed limit.

Beckworth argues that the Fed should abandon its inflation target for a nominal growth target instead. This would allow the Fed to tolerate higher inflation during periods of low growth (as we are experiencing now), to be made up for with periods of lower inflation when growth is strong.

Not everyone buys Beckworth’s argument that nominal growth targeting will be a cure-all. Former Treasury secretary Larry Summers, for instance, has given a half-endorsement to the idea, but has been much more forceful in his argument that today’s low inflation environment is a signal that governments around the world should be spending more to prop up weak demand.