http://www.ecocn.org/thread-74986-1-1.html
[Free exchange] [2012.07.24] Rethinking macro 宏观经济反思 Rethinking macro 宏观经济反思
Jul 26th 2012, 19:59 by R.A. | WASHINGTON
From The Economist print edition
THIS week's Free exchange column takes a look at whether economist Milton Friedman, who would have turned 100 on July 31st had he lived, would be urging the Federal Reserve to do more or less to help the economy. Quite plausibly, the piece concludes, he would have recommended doing more: 这个星期的“Free exchange column”关注了经济学家米尔顿·弗里德曼——到7月31日，他应该就100岁了，如果他还在世的话——是否会强烈要求联邦储备系统为经济做出或多或少的帮助。似乎很有道理的是，除了这一条之外，他一定会要求（联邦储备系统）做得更多：
Today, critics of Fed easing point to Friedman’s preference for stable money-supply growth, to help establish central-bank discipline. John Taylor notes that money growth was quite rapid during the recent recession. Hawks also cite Friedman’ s anti-inflation crusade. To Allan Meltzer, “The Fed’s plan to increase inflation [through QE]…is a large step away from the policy that Milton Friedman favoured.” It is more like old Keynesianism, which held that faster inflation could buy a permanent drop in joblessness. Friedman rejected this. He contributed to the “natural rate hypothesis”, that efforts to push employment above an economy’s limits simply bid up wages, raising inflation.
如今，美联储放松的评论家们指出了为了建立中央银行的制度，米尔顿·弗里德曼对稳定的货币供给增长策略的偏爱。约翰·泰勒指出，在最近的一次经济萧条中，货币的增长速度颇为迅速。Hawks也引用了米尔顿·弗里德曼发起的反通胀运动。至于艾伦·梅尔策 ，他说：“美联储提高通货膨胀的计划（通过“量化宽松政策”）……是与米尔顿·弗里德曼所主张的政策大相径庭的。”（美联储）更像是老的凯恩斯主义者，他们认为更快的通货膨胀可以换来失业率的持续下降。弗里德曼反对这一观点，他赞成的是“自然失业率假说”，即推动就业超出经济限额的努力只会哄抬工资，提高通胀。
Yet Friedman also considered variables other than prices. A characteristic of both the contraction of the 1930s and the Japanese stagnation of the 1990s, he noted, was the drag of tight money on nominal GDP. Reversing this would “have the same effect as always,” he said: “output will grow, and after another delay, inflation will increase moderately.” He grew flexible, as well, concerning money-supply rules. In 1984 he wrote that slow, steady monetary growth was “not a necessary implication of monetarist theory”. And when an economic crash in 1990s Japan gave way to a feeble recovery and deflation, Friedman recommended a monetary “kiss of life” in the form of QE. 当然，米尔顿·弗里德曼也会考虑除价格外的其他变量。他指出，20世纪30年代的经济收缩和20世纪90年代日本的停滞有一个共同的特点，那就是紧缩货币给名义GDP带来的阻力。（要）扭转这种经济危机会“有一如往常的影响”，他说，“产值会增长，接着，在另一次迟滞之后，通胀水平也会有适当的增长”。弗里德曼也考虑到了货币的供给规则，因此他的结论变得灵活了。在1984年，他写道：缓慢的，稳定的货币增长“并不是货币主义理论的必要内涵”。当20世纪90年代日本的经济崩溃慢慢恢复为缓慢的恢复和通货紧缩时，弗里德曼建议进行一次货币的“生命之吻”，即“量化宽松政策”。
Unfortunately, we can't know how he would have reacted. It falls to today's monetary practitioners to decide what to do.
遗憾的是，我们不能得知弗里德曼会怎样回应了。轮到今天的货币当局去决策了。
I gave a talk today on precisely that subject: what the Fed should do and why. The why, I conclude is rooted in a rethinking of the meaning of the past century's great monetary inflection points. It's a bit long, but have a look if you care to:
我今天就“美联储应该怎样做，为什么”这一主题进行了一次演讲。有关为什么，我认为那建立在对上个世纪的巨大货币政策变化时点的反思的基础上。我的演讲有一点长，但是如果你关心这个问题，便读一读：
The title of my talk today is “Ben Bernanke’s economy: Can the Fed deliver morning in America?” It’s fairly remarkable,when you think about it, that we find ourselves asking such questions today. Much of my first exposure to economics, and life, came in the 1990s. It is remarkable to think back on the prevailing attitude toward stabilization policy at the time,which was something like omnipotence on the part of the Fed. Inflation was a slain beast. Financial turmoil was nothing the committee to save the world couldn’t handle. And unemployment, in Paul Krugman’s phrase, was sure to be what Alan Greenspan wanted it to be, plus or minus a random error reflecting the fact that he is not quite god. Krugman wrote that in1997, in a column for Slate entitled “Vulgar Keynesians”. I recommend Googling and reading it; doing so is a perfect way to capture the upside-down nature of today’s macroeconomics.
今天我演讲的题目是《本·伯南克的经济论：美联储能使美国“变天”吗？》。想想看，今天，我们发现自己问出这样的问题，这是相当惊人的。我对经济和生活的第一次接触，大部分是开始于20世纪90年代。回想一下那时对于稳定政策的主导性态度是非常好的，那时的主流思想认为美联储几乎是全能的。通胀是一种嗜杀的猛兽。金融风暴并不是拯救世界委员会不能处理的。而失业率，正如保罗·克鲁格曼所说，肯定能够成为艾伦·格林斯潘所希望的样子，一个正的或负的随机误差只是反映出他并不是真正的上帝。1997年，克鲁格曼写到这点，在一篇名为《庸俗凯恩斯主义》的column for Slate中写到了这一点。我推荐搜索一下并读一读，这是捕捉当下混乱的宏观经济形势的一个很棒的方法。
What happened after 1997 to turn the world upside down we will come to shortly. But I think it’s best to start by recapping the events that took us to that moment in the late 1990s, starting with the formative macroeconomic experience: the Great Depression. Indeed, if you want a simple way to think about the history of macroeconomics it’s this: economics was shocked by the calamities of the interwar years, it spent 30 years debating what that experience meant, and then spent 30years seeing if it had arrived at the right answer. And at the end of that 30 year test, I think we can say that it got one important thing right, and one important thing wrong.
关于1997年以后发生的混乱了世界的事情，我会讲得快一点。但是我认为最好还是从扼要重述那件把我们带入20世纪90年代末期这个时点的事件开始，从宏观经济体系形成的经历——经济大萧条开始讲起：事实上，如果你想要一个研究宏观经济历史的简单办法，那是这样的：经济受到两次战争间的那些年的巨大灾害的冲击，人们用了30年去辩论经济大萧条的经验意味着什么，又用了接下去的30年去检验他们得到的结论是否正确。我想，在第二个30年的末尾，我们可以这样判断：人们得出可一个重要的正确结论，和一个重要的错误结论。
To an economic historian, the Depression inspires a kind of morbid fascination, like contemplating the campaigns of Genghis Khan or the spread of the Black Plague. The details are astounding. In America, net national income fell in half.Equity prices dropped 90%. The price level fell by a third. It was an unbelievable disaster, made all the more painfully poignant by the economic revelation that it was largely a preventable catastrophe. The Depression was manmade.
就像钻研成吉思汗的战役或黑死病的传播一样，对一个经济学历史学家来说，经济大萧条散发着一种病态的魔力。其中的细节是惊人的。在美国，国民收入净值下降了一半，股票价格下降了90%，价格水平则下降了三分之一。这是一场令人无法相信的灾难，这场灾难令一切变得了更加痛苦辛酸，因为经济启示出，它在很大程度上是一场可以预防的灾难。经济大萧条是人为的。
That it was manmade became the economic consensus relatively quickly. British economist John Maynard Keynes decisively carried several of the arguments of the day. The Depression, it was widely agreed, was a problem of demand. It was a colossal market failure. And it was susceptible to stabilization policy by the government. On the basis of these insights, Keynesians came to dominate the early postwar economic order. They built complex economic models with substantial roles for government management. They focused on fiscal policy as an engine of stabilization, and they largely relegated the central bank to a secondary policy role.
这一认识相对迅速的成为了经济领域的共识。英国经济学家约翰·梅纳德·凯恩斯肯定地提出了几个论据。经济大萧条，是需求的问题，这一观点得到了广泛的认同。这是一个巨大的市场失灵，并且，受到了政府稳定政策的影响。以这些见解为基础，凯恩斯主义者获得了战后经济的支配权。他们建立了一种复杂的经济模式，在其中，政府管理扮演了着重要的角色。他们专注于财政政策，将其当作经济稳定的发动机，他们大力降低中央银行的作用，将其降低到一个辅助性政策的角色。
But the postwar debate over the meaning of the Depression quickly intensified. Where many prominent Keynesians held that central banks were relatively helpless during the Depression, because interest rates fell to very low levels, others, most notably Milton Friedman, suggested that nothing could be further from the truth. On the contrary, he said, interest rates were low because the Fed had pursued a too-tight monetary policy. It raised interest rates to prick the stock bubble of the late 1920s and to defend gold reserves, and when higher rates squeezed banks into trouble, it failed to step in to save them or to offset the fall in the money supply when they closed en masse. The Fed was anything but helpless when interest rates hit zero, he argued. On the contrary, open-market securities purchases, what we might now call quantitative easing,would raise the money supply, halt deflation, and arrest the economy’s downward spiral.
但是，战后，关于经济大萧条的含义的辩论迅速激烈起来了。一些杰出的凯恩斯主义者认为中央银行在经济大萧条中作用较弱，因为利率下降到了非常低的水平；而其他人，最显著的是弗里德曼，则认为这种论断完全不正确。他认为，完全相反地，利率低是由于美联储继续实行了过紧的货币政策。美联储为打破20世纪20年代末期股票市场上的泡沫，同时保护黄金储备而提高利率；而当高利率使众多银行陷入困境的时候，它没有介入拯救他们；当众银行集体关闭的时候，它也没有采取举措去抵消货币供应量的下降。他认为，美联储对利率下降到零毫无办法。与此相反，公开市场购买证券，我们现在可能叫“量化宽松政策”，将提高货币供应量，停止通缩，并停止经济的螺旋式下降。
In fact, what the Depression showed, Friedman argued, was that monetary policy was extremely powerful, that the central bank had an important influence over money supply, and that in the short run this could have a significant impact on the real economy. Keynesians disagreed. They disagreed that the price level was entirely within the central bank’s control.They believed that there was a “demand” in the economy not intimately bound up with monetary policy. And they thought that you could use fiscal and monetary policy to boost the economy on an going basis without creating inflation, so long as you controlled the supply-side causes of rising prices, like high union wages demands or price increases by opportunistic businessmen.
弗里德曼指出，事实上，经济大萧条所表明的，是货币政策是非常强大的，而中央银行对货币供给有着非常重要的影响，这在短期内可以对实体经济产生非常重要的影响。凯恩斯主义者不同意。他们不同意价格水平完全由中央银行控制。他们认为，在经济中存在着某种“需求”，这种“需求”是并非与货币政策联系得那么紧密的。并且，他们认为，只要你控制物价上涨的供给方面的原因，如高的工会工资需求或投机的商人提价，你可以利用财政和货币政策保证经济的持续繁荣，却不发生通货膨胀 。
This argument came to a head in the 1970s, when inflation began to spiral out of hand. Keynesians suggested that“incomes policies” or wage and price controls, could fix the problem, while Friedman’s monetarists argued that only the Fed could bring inflation to heel. Friedman won the rhetorical battle, largely because wage and price controls were all but useless in stopping inflation. And then, when Paul Volcker became chairman of the Fed, raised interest rates dramatically,and brought inflation crashing down to tolerable levels, Friedman won the intellectual battle.
20世纪70年代，随着通货膨胀的失控螺旋上升，这场辩论达到高潮。凯恩斯主义者认为收入政策，或工资和价格管制可以解决问题，而弗里德曼等货币主义者则认为只有美联储可以结束通胀。弗里德曼赢得了语言上的斗争，很大程度上因为工资和价格管制在结束通货膨胀上根本不管用。接下来，等到保罗·沃尔克成为美联储主席并且显著提高利率，控制通货膨胀到可忍受的水平之后，弗里德曼又赢得了学术上的斗争。
That was the critical moment. That was the point at which the postwar arguments over the meaning of the Depression were settled. And in the calm created by Friedman and Volcker a New Keynesian consensus emerged, rooted firmly in monetarism.
这是关键时刻。这是战后的辩论结束，经济大萧条的含义最终得到结论的时刻。在由弗里德曼和沃尔克创造的平和中，一种深深扎根于货币主义的新的凯恩斯共识出现了。
That consensus consisted of a few key tenets. Money matters. The central bank controls inflation. The central bank, by controlling inflation, can dramatically reduce the volatility of business cycles. And the optimal way to control inflation was to keep it low, stable, and predictable. The pain of the Depression was down to deflation, in this view, and the pain of the1970s to accelerating inflation. But at last, central banks knew what to do. And so began the 30-year test.
这个共识包括几个关键原则：钱的问题。央行控制通货膨胀。央行通过控制通货膨胀，可以大大减少商业周期的波动。还有，控制通货膨胀的最佳方式是将其保持在低，稳定并且可预见的程度。根据这种观点，经济大萧条的痛苦是通货紧缩，以及20世纪70年代加速的通货膨胀的痛苦。但最终，央行知道该怎么做。因此，开始了30年的测试。
In the early going, things could scarcely have gone better. The Volcker disinflation ushered in what many of us call the Great Moderation. Business cycle expansions became decade-long affairs, recessions were rare, short, and relatively shallow, and inflation went from mild, to subdued, to entirely domesticated.
在刚开始时，几乎已经完美了。沃尔克的通货紧缩，迎来了我们许多人称之为“大缓和”的阶段。商业周期的扩张长达十年之久，而（在这过程中）经济衰退却罕见、短期并且相对较浅，通货膨胀从轻微，到减弱，以至于完全柔和了。
Toward the latter end of the second great expansion of this era, we catch back up to Paul Krugman, singing Greenspan’s praises. It wasn’t long thereafter, however, that cracks began to appear in the facade. Japan’s powerful economy, which inspired fear in America in the 1980s, lost its footing in the early 1990s and was driven into a nasty recession by the Asian financial crisis of the late 1990s. But while emerging Asia quickly recovered from the crisis, Japan sank into stagnation.Growth seemed to stall out, and deflation became a concern. America’s economists, including Ben Bernanke, gazed from their perch in America, where central bankers were kings, and concluded that weakness prevented the Bank of Japan from doing what was necessary to restore healthy growth. Milton Friedman surveyed the scene and called for quantitative easing. Bernanke said the Bank of Japan was constrained by “self-induced paralysis”, and could restore prosperity if it wanted to, through QE, or devaluation, or other aggressive monetary action.
接近这个时代的第二次大扩张快结束的时候，这就是保罗·克鲁格曼歌唱他对格林斯潘的赞誉的时候。 然而，那之后不久，裂缝开始出现在表面。日本在20世纪80年代激起美国恐惧感的强大经济，在90年代初就开始动摇，并且在90年代末亚洲经济危机到来时彻底陷入一场严重的衰退。增长似乎停滞了，通缩成为一个问题。但是，亚洲新兴经济体迅速从危机中恢复了，而日本却陷入了停滞。 美国的经济学家们，包括本·伯南克，从中央银行老大的美国，盯着日本，并且得出结论：日本银行的无力使他们（日本银行）难以实行恢复经济健康增长的举措。米尔顿·弗里德曼调查了情况，呼吁实行“量化宽松政策”。伯南克说，日本银行是自我强迫陷入“自我瘫痪”，如果他们愿意，他们可以通过实行“量化宽松政策”或通过货币贬值或其他积极的货币行为恢复经济的繁荣。
Japan, in other words, suffered from peculiarly Japanese weaknesses. Macroeconomics was not to blame. At Milton Friedman’s 90th birthday, in 2002, Bernanke, then a new Fed governor, mused on the damage of the Depression and told Friedman, “You’re right. We did it. We’re very sorry. But thanks to you we won’t do it again.”
换句话说，日本，是遭受了“日本特色”的软弱，并不是宏观经济的问题。2002年，在米尔顿·弗里德曼的90岁生日时，伯南克——这是他已经是当时的美联储主席了——沉思过大萧条的损失后告诉弗里德曼：“你是对的。我们错了，我们很抱歉。但是归功于你，我们不会再犯那样的错了。”
Meanwhile, in Japan, here’s what happened. The Bank of Japan initially promised to keep rates at zero “until deflationary concerns subside”. Finding this ineffectual, it shifted to QE, aggressively buying assets between 2001 and 2006. By 2006,inflation had stabilized at low but positive rates. Seemingly satisfied, the Bank of Japan halted QE, drew down the level of bank reserves and raised its benchmark interest rate. Growth and inflation plodded along in low but positive territory until 2008, when the economy lapsed back into contraction and deflation. Which has once again triggered BoJ intervention to move prices back into positive territory.
与此同时，在日本，发生了这样的事：日本银行最初承诺“直到通货紧缩的担忧平息”将利率保持在零的水平，当发现这招没用之后，又转而实行“货币宽松政策”，在2001年到2006年间疯狂的购买资产。到2006年，通胀率稳定在一个低但是正的水平。日本银行似乎是满意了，因此停止了“货币宽松政策”，降低了存款准备金率，提高了利率基准点。（从那以后，）经济增长和通胀率一直保持着低且正的增长——直到2008年经济坠回到紧缩和通缩，这又一次触发了日本银行对经济的干预，以便调整物价到正向的范围。
There is no overstating Japan’s economic disaster. Its real income per capita rose to 90% of America’s in the early1990s, but has since fallen back to 70% of the current American level. This failure has inspired many idiosyncratic explanations: demography, a zombie banking system, a corrupt political class, and so on. But idiosyncratic explanations look much less compelling now, with the rich world’s large economies following on Japan’s heels.
对日本的经济灾难进行毫不夸张的描述：在20世纪90年代初，日本的人均实际收入已经上升到了美国的90%，而现在（2008年）却下降到了美国同期的70%。这次失败引发了许多种解释：人口、顽固的银行体系、腐败的政治等等。但是随着日本成为世界上很大的经济体，这些多种多样的解释现在听来已经并不那么棒了。
When the crisis of 2008 shrunk, central banks responded by following Milton Friedman’s playbook. They stepped in to prevent cascading failures in the banking system. They deployed QE to fend off deflation. And they succeeded in bringing inflation back to rates close to target, typically around 2%. When inflation has threatened to fall back toward zero, they’ve deployed new rounds of QE. The commitment to low and stable inflation is flawless.
当2008年经济危机的缩小时，中央银行们的反应是按照米尔顿·弗里德曼的剧本行动。他们开始在银行系统中防止倒塌型的失败。他们部署“量化宽松政策”来抵御通货紧缩，成功的将通胀率提升回到接近目标的程度，典型的是2%附近。当通胀率面临下降回零的威胁时，他们实行新一轮的“量化宽松政策”，完美的履行着保持低且正的通胀率的承诺。
And yet the rich world looks ever more like Japan. The Fed has drawn a line at 2% inflation rather than 0% inflation, but the impact seems not to have mattered much. As in Japan, American output has come in consistently at or below trend,and virtually none of the output gap that opened up during the recession has been closed. As in Japan, the rise in unemployment that accompanied the economic slowdown has retreated a bit, but has come nowhere close to pre-crisis levels. And as in Japan, long-run interest rates have collapsed despite rising debt loads, seemingly signalling expectations of a long, long period of extremely disappointing growth.
然而，发达国家（美国.？）看起来从没和日本这么相像过：美联储已经划出通胀率的标准为2%，而不是零，但是这举措的影响似乎是微乎其微的。和日本一样，美国的产出已经持续的保持达到或低于（标准）的趋势，在衰退期间开出的产出缺口几乎全部没有关闭。和日本一样，伴随经济减速的失业率上升减慢了一点点，但已经根本没法接近危机前的水平了。和日本一样，尽管债务负担上升，长期利率却已经崩溃，似乎是预示着在未来很长时间内的增长预期会极度令人失望。
Now, it’s possible that this is coincidence. It’s possible that structural economic factors in Japan have been replicated, a decade later, across the rest of the rich world -- that a technological slowdown, for instance, hit Japan in the 1990s and only later settled on America and Europe. But this seems very unlikely. It looks very much like the fault lies with the macroeconomic policy regime.
的确，这可能是巧合。可能是20世纪90年代击倒日本的结构性经济因素，例如，技术的减缓，在10年以后，绕过了其他的发达国家，恰好不偏不倚地被复制到了美国和欧洲。但这似乎可能性非常之小。看起来错误很有可能在于宏观经济政策体制。
So what is the fault? By now the pattern in America’s recovery is unmistakable; I think we’ve actually come to expect it.Growth and employment gain momentum, then some headwind strikes. Growth slips back toward zero, hiring falls below levels sufficient to reduce the unemployment rate, and inflation expectations slowly sink. When the outlook for inflation is weak enough to get the Fed worried about deflation it intervenes. Inflation expectations then rise, employment and hiringrecover, and things look promising again. Hopes that the Fed might sustain its intervention then disappear. And then someheadwind strikes.
那么，这个错误是什么呢？到现在，美国经济复苏的格局是明白无误的，我认为我们实际上已经开始期待它了。增长和就业增加了动力，接着，发生一些逆风的罢工，增长滑落回零，雇佣率下降到足够降低失业率的水平以下，接着，通胀预期缓慢下降。当通胀的预期弱到使美联储担心通缩的时候，它开始干预。于是通胀预期上升，就业率和雇佣率回升，事情看起来又充满希望了。美联储维持其干预行为的需要消失了，然后，发生一些逆风的罢工。
At no point is there anything resembling growth fast enough to make up some of the ground lost, relative to trend, during the recession. By some variables, we’re falling further behind.
在萧条期间，相对于趋势来说，从没有过任何东西的增长速度可以快到弥补一些失地。从一些变量上来说，我们落后得很远。
The key number in this dance is 2%. That’s the threshold. The Fed targets a 2% rate of inflation. It says 2% is a symmetrical target but in practice it functions more like a ceiling. The Fed’s preferred measure of inflation has risen above2% in only a handful of months since the crisis of 2008. Economic troubles in Britain and Europe are qualitatively different,but they also suffer from this cap. The 2% inflation target exerts a strong constraining force on monetary policy.
此过程中的关键数字是2%。这是一个门槛。美联储以2%为通胀率的目标。它声称2%是一个均衡的目标，但事实上，2%更像是一个上线。从2008年经济危机之后，美联储更乐意使通胀率仅仅在短短几个月以内可以超过2%。英国和欧洲的经济困境有本质上的不同，但他们也遭受着这一魔咒。2%的通胀率目标，是货币政策中一个强大的制约。
This is perverse. If you ask Ben Bernanke, he’ll tell you, quite forthrightly, that the Fed could do more to boost growth and employment, but that it doesn’t want to risk confidence in the 2% target. And when one thinks on the power of that 2%number, one begins to reexamine the lessons of the Depression and of the 1970s.
这是不正确的。如果你去问本·伯南克，他会很坦率地告诉你，美联储可以有更多令经济和就业更加繁荣的办法，只是它不想在对2%的目标的信心上冒险。当一个人开始怀疑2%指标的力量时，他会开始再次审查大萧条和20世纪70年代的教训。
Read Friedman again and you can see the possibility of a different interpretation of economic history. He says monetary policy can influence nominal output—total spending in the economy, unadjusted for inflation. In the short run, he says, this can influence real variables like real GDP growth and employment. In the long run, however, it can only affect inflation.
重新研究弗莱德曼，你会发现对经济史有一个不一样的解释的可能性。他说，货币政策可以影响名义产出——一个经济体中的未经通货膨胀调整的总消费量。他还说，在短期内，货币政策可以影响一些实际变量，如实际GDP的增长量和就业率；而在长期内，货币政策只能影响通胀水平。
But the total amount of spending in the economy is nothing more and nothing less than aggregate demand. If demand were higher, people would have spent more. If it were lower, less. Monetary policy, at all times, controls demand. In the short run, higher demand will generate an uncertain mix of changes in the economy—some price and wage increases but also some real output increases—so that higher inflation is, at all times, likely to accompany higher demand. There is no pure, sterile stimulus that the Fed can deliver that will bring higher real growth without higher prices, as Bernanke now claims he would like to do.
但是，经济中的总消费量不会比总需求多，也不会比总需求少。如果需求变多了，人们就会消费得更多；如果需求变少了，人们消费得就少。货币政策始终控制需求。在短期内，更高的需求对经济中的变化产生难以预测的混合影响——如一些价格和工资的上涨，但同时也会带来一些实际产出的上升——因此，更高的通货膨胀可能会总是伴随着更多的需求。美联储不可能像伯南克现在所声称的他愿意做的一样，释放出纯净不含杂质的刺激，带来更高的实际的经济增长的同时，却不引起价格的上升。
But these higher prices signal accelerating inflation—the scourge of the 1970s—only to the extent that they become embedded into wage increases. And when there is broad slack in the economy, that is very unlikely to happen. In the longrun, higher demand raises inflation only to the extent that the economy faces supply constraints. Only if it’s operating at potential.
但是这些预示通胀加速的价格上涨信号（20世纪70年代的祸害），也仅仅是达到被嵌入到工资上涨的程度。并且，当经济中出现广泛的松弛时，这很难发生。在长期中，更高的需求只会将通胀增加到使经济体面临供给约束的程度。除非它在潜在里发挥作用。
So now let’s rerun the crises of the past century. The key fact of the Depression was not deflation; it was plunging demand; deflation was the symptom. A central bank commitment to fight deflation therefore leaves some monetary fruit unplucked. The recent crisis was much less severe than the Depression because central banks thought deflation prevention was critical; in fighting deflation they couldn’t help but prevent a big demand collapse. But having beaten deflation they were at a loss what to do next. The answer was simple: create more demand! But that was beyond the consideration of inflation-obsessed central bankers.
那么，现在，让我们重新模拟上个世纪的经济危机。大萧条的关键事实不是通货紧缩，而是持续下降的需求，通货紧缩仅仅是一个征兆而已。因此，中央银行应对通货紧缩的举措使一些货币没有发挥应有的效果。最近的一次经济危机远远没有那次经济大萧条那么严重，是因为中央银行认为，控制通货紧缩是关键的，而他们在应对通货紧缩的过程中本没有打算却意外的阻止了需求的崩溃。但是，战胜了通货紧缩之后，他们却不知道下一步该做什么了。答案很简单：制造更多的需求！但是这就超过了那些专注于关注通胀率的中央银行家的考虑范围了。
Take the 1970s. The dynamic there was no more and no less than the fact that demand was running beyond the economy’s capacity to produce. Higher demand had nowhere to go but into higher prices. And as higher prices became built into expectations, wage demands rose, and accelerating inflation resulted. Central banks then resolved to rein in inflation. It took a recession to re-establish low inflation because Volcker needed to convince people that the Fed could control inflation and would control inflation, in order to reset expectations. But once that was established, control overinflation was simply a side effect of demand, constrained at or below the supply capacity of the economy.
以20世纪90年代为例。事实就是：需求已经超过了经济体的生产能力。更高的需求无处得到满足，结果就是哄高了物价。随着更高的价格预期，工资也要求上升，结果就是加速的通胀。然后，中央银行就下定决心要控制通胀。重新建立低的通胀水平之前经历了一次萧条，因为为了重建预期，沃尔克需要让人们对美联储充满信心，相信美联储可以并且会控制住通胀。一旦这种信心建立起来，控制超通胀便仅仅是将需求控制在经济体生产能力或以下的副作用。
Bernanke now argues as though it would take another Volcker recession to defeat high inflation. But the public no longer needs to be convinced that the central bank has the ability to control inflation -- that is well established. It just needs to be told under what conditions it will do that. And that’s fairly straightforward: when inflation dynamics begin to signal that supply constraints are beginning to bind.
现在，伯南克声称，似乎需要另一个沃尔克时代的萧条去抵制过高的通货膨胀。但是现在公众不再需要树立中央银行有能力控制通胀的信心了——这种信心早就建立好了。美联储仅仅需要告知公众，在什么情况下美联储才会采取举措控制通胀。而这再直接不过了：当通货膨胀的动态开始预示出，供给约束开始陷入窘境的时候。
What would that mean in practice? Central banks should focus their efforts on measures of demand -- nominal GDP,nominal income, nominal spending—rather than measures of inflation. If nominal GDP is at a level that’s inconsistent with full employment, demand is too low and the central bank should do more. That might take inflation above some arbitrary level, and that’s totally fine. It won’t stay above that arbitrary level and accelerate unless the central bank keeps raising demand indefinitely. This is not to say that there are no costs to having 4% inflation for a year rather than 2%. There are surely some efficiency costs to changes in relative prices. But if the alternative is a trillion dollar output gap and 6 million unnecessarily unemployed workers, that’s probably a pretty good trade-off to make.
而在实践中，这意味着什么呢？中央银行应该努力关注它们对需求的度量——名义GDP、名义收入、名义消费——这比关注通胀率更为重要。如果名义GDP处于一个与充分就业不符的水平上，说明需求太低了，中央银行应该采取一些行动。这可能会将通胀率调整到一个任意的水平，但那完全没有问题。除非中央银行保持无止境的提高需求，通胀率不会保持高于那个任意的水平，也不会上涨。这并不是说，一年里将通胀率保持在4%的水平，而不是2%，是没有成本的。相对价格的变化，必然会花费一些有效的成本。但是，如果可以弥补一万亿美元的产出和6百万的不必要的失业，这可能是一个相当不错的选择。
We learned a hugely important lesson from the Depression—that central banks could influence the economy and prevent demand-side macroeconomic disasters. But we took a wrong turn in thinking that the way they did this was by moderating inflation. It was as if we discovered a magical sword in the woods and then went about confronting enemies by whacking them with the sheath.
我们已经从大萧条中吸取了巨大的重要教训，那就是中央银行可以影响经济，并且可以防止需求方面引起的的宏观经济危机。但是我们错在：我们以为中央银行发挥这方面作用的方法是控制通胀。这就像我们在树林里发现了一把有魔力的宝剑，但我们给它重装上了剑鞘后上前线去与敌人战斗。
We can move past this intellectual limitation. Monetary policy can influence demand, plain and simple. This economy could plainly use more of it; millions of unemployed workers are a testament to that. Not to do more to get them to work is to leave the sword at one’s side during a battle, because it looks prettier there. And the Fed should be careful. If it doesn’tuse it, someone might try to take it away.
我们可以将这一页翻过去了：我们受到这种智力限制的这一页。货币政策可以直接而简单的影响需求。我们的经济体可以清楚地把它利用的更好，数以百万的失业工人证明了这一点。不做更多事让他们去工作，就是因为这样使宝剑看起来更加漂亮而使它的一侧藏在剑鞘里。美联储应该小心了。如果它不使用（货币政策这把宝剑），其他人也许会努力把它拿走。 |
发表于 2012-8-13 17:21
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发表于 2012-8-13 22:42
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