美联储量化宽松政策的另一个好处

The Federal Reserve has been explicit about why it has been holding short-term interest rates near zero and has purchased $2.5 trillion in Treasury and government-backed mortgage bonds to push long-term rates to once-unimaginable lows:

美联储(Federal Reserve)为什么一直把短期利率维持在接近于零的水平，并购买2.5万亿美元的美国国债和政府担保的按揭债券、从而将长期利率压至以前不可想象的水平？美联储对此问题的回答一直是清晰明确的。

Not only does it hope cheap money will make borrowing and spending more attractive to businesses and consumers. It also wants to chase investors out of super-safe U.S. Treasurys and mortgages and into stocks, corporate bonds and other assets riskier than Treasurys. Boosting those prices, the central bank figures, will make households richer, increase the value of collateral that banks hold against loans and encourage executives─always happier when stock prices are rising─to invest.

它不仅希望借助于低息资金让企业和消费者更愿意借钱、花钱，还希望把投资者赶出超级安全的美国国债和按揭债券，让他们投资股票、公司债券和其他比美国国债风险高的资产。美联储盘算，抬高这些资产的价格将增加家庭财富、提高银行所持贷款抵押物的价值，并鼓励企业经理人投资──股价越涨，他们总是越高兴。

Chairman Ben Bernanke and his allies at the Fed think all this is working as they had hoped, though they caution regularly that it isn't enough to resuscitate the U.S. economy nor is it without risks. Critics argue that it isn't doing much good─and that the risks are greater than Mr. Bernanke realizes. Now new Fed governor Jeremy Stein, a Bernanke backer, is arguing this bond-buying might have hidden benefits.

美联储主席贝南克(Ben Bernanke)和他在美联储内部的盟友认为，这一切都在按他们的预想发挥著作用。不过他们也经常提醒说，仅此不足以让美国经济复元，并且这一做法也不是没有风险的。批评者说，这一政策没有带来多大好处，而且风险比贝南克意识到的要大。现在，支持贝南克的新任美联储理事斯坦(Jeremy Stein)说，购买债券的措施可能还带来了看不见的好处。

One oft-cited risk the Fed is running is that keeping rates very low for a long time could lead investors, big and small, to take ever-greater risks as they seek investments that promise better returns. That, in turn, could create a new set of financial bubbles. 'These concerns should be taken very seriously, and a lot of work at the Fed is devoted to monitoring such risks,' Mr. Stein said in a speech last month. '[T]here is some qualitative evidence of reaching-for-yield behavior in certain segments of the market, but we are not seeing anything quantitatively alarming at this point. Of course, the worry is that one often sees only the tip of the iceberg in these kinds of situations.'

人们常说美联储面临着这样一个风险：长时间把利率维持在非常低的水平，可能会导致大大小小的投资者在寻找有望产生更大回报的投资产品时承担越来越大的风险，进而有可能产生一系列新的金融泡沫。斯坦在上个月的一篇讲话中说，这些担忧应该非常认真地对待，美联储所做的很多事情都是为了监测这些风险。他说，虽然有一些质化证据表明市场某些部分存在只顾收益率的行为，但目前我们没有看到任何值得警惕的量化证据；当然，令人担心的一点是，这些情况下人们看到的问题常常只是冰山一角。

It isn't hard to spot bubble candidates. The price of farmland has been soaring. The U.S. Department of Agriculture's measure has risen 28% in two years. And Merrill Lynch's index of high-yield debt─borrowing by companies politely labeled 'below investment grade'─is up 12% in the past year.

不难找到一些可能出现泡沫的领域。农地价格在大幅上涨。美国农业部的农地价格指标两年里上涨了28%。美林(Merrill Lynch)的高收益债券指数在过去一年上涨了12%。（高收益债券指“投资级以下的公司债券。）

But Mr. Stein pointed to one way in which the Fed's bond-buying, quantitative-easing extravaganza might be contributing to financial stability. It is encouraging companies to rely less on short-term borrowing. That is welcome. 'A major source of problems during the recent crisis,' he said, was that firms, particularly in finance, 'were relying too much on short-term debt.' That left them exposed when markets panicked in 2008 and rolling over short-term debt became difficult, often impossible.

但斯坦指出，美联储通过购买债券实施的大规模量化宽松政策，可能正以某种方式起着维护金融稳定的作用：它鼓励企业降低对短期借款的依赖。这是一件好事。斯坦说，最近这场危机期间的一个重要问题来源是，企业(特别是金融企业)过于依赖短期债务。这种情况使它们在2008年市场陷入恐慌时无法躲避，短期贷款的展期变得困难起来，经常是根本无法展期。

Before Mr. Stein left Harvard for the Fed, he and colleagues Robin Greenwood and Samuel Hanson showed statistically that when the federal government does a lot of its borrowing at shorter maturities, companies tend to do a lot of their borrowing at longer maturities, and vice versa. By reducing the supply of long-term Treasurys in the market, the Fed's heavy purchases are akin to the government borrowing more short-term.

在斯坦离开哈佛大学到美联储任职之前，他与同事格林伍德(Robin Greenwood)和汉森(Samuel Hanson)的统计数据显示，当美国联邦政府开始大量短期借债时，企业往往也会大量举债，且期限较长，反之亦然。美联储大举购债减少了市场上长期国债的供应量，这种做法类似于政府更多地借进了短期债务。

There is a wrinkle. While the Fed is subtracting from the market's stock of long-term Treasurys, the Treasury itself seems to be fighting the Fed. It is adding to the supply of long-term Treasurys by selling more of them. The average maturity of the Treasury's debt outstanding has been growing for years. At the end of September, it was 64.4 months, well above the 30-year average of 58.1 months.

但这里有个问题。就在美联储减少市场上的长期国债之际，美国财政部似乎正与之进行较量，即出售更多国债来增加长期国债的供应。美国财政部未偿债务的平均期限多年来一直不断增加。截至今年9月底，这一期限为64.4个月，远高于30年来58.1个月这一均值。

The Treasury's official explanation: We're trying to finance the government at the lowest cost to taxpayers. We aren't using a borrowing mix to influence the macro economy, and we aren't coordinating with the Fed on this. As the chart accompanying this column illustrates, the Fed's recent purchases of long-term Treasurys have more than offset the Treasury's moves in the opposite direction.

对此美国财政部给出的官方解释是：我们正努力以让纳税人承担最低成本的方式来为政府融资，我们并不是在使用贷款组合影响美国宏观经济，而且我们也没有就此事与美联储协调一致；正如随附表格显示的，美联储近期购买长期国债的举动与财政部的举措背道而驰，完全抵消了我们的所作所为。

Business is reacting as the academics predicted: 77.8% of non-financial corporate borrowing is for a year or more at the 2011 tally, up from 69.7% just before the crisis, according to the latest Greenwood-Hanson estimates. Their chief financial officers are taking advantage of long-term rates they don't expect to see again in their lifetimes. Financial firms are doing the same, with an extra prod from regulators pushing them to be less vulnerable to droughts in the short-term money markets. 'All else being equal, this development is a good thing from a financial-stability perspective,' Mr. Stein argued.

企业界的反应与学术界的预测并无二致。据格林伍德和汉森最近的估算，2011年举债的非金融类企业中有77.8%的贷款期限为一年或以上，高于金融危机前夕的69.7%。这些企业的首席财务长正在抓住眼下的时机，他们认为这辈子可能再也遇不到如此低水平的长期利率了。金融类企业也在这么做，原因是监管方专门出手干预，好让它们在短期货币市场的“枯竭期不那么不堪一击。斯坦坚持认为，如其他条件相同，那么从金融稳定的角度看，这是件好事。

Indeed it is─with a caveat. If borrowers are going long, so are investors. And when interest rates rise, as they surely will, investors will have big mark-to-market losses. (When bond yields go up, bond prices go down.)

没错，是好事，但需注意一点。如果借款人这么做，投资者也会跟着这么做。利率升高时(这是一定的)，投资者会蒙受巨大的按市值计价亏损。(债券收益率上涨，债券价格下跌。)

For buy-and-hold investors like pension funds, that isn't a big deal; for others, it can be destabilizing. Fed old-timers recall 1994: The Fed raised interest rates after a long plateau, startled the bond market and sank Orange County, Calif., and a few other bond investors.

对于投资退休基金、秉持买入且持有策略的投资者而言，这不是什么大事，但对其他投资者来说却可能是个不稳定因素。据长期供职于美联储的雇员回忆，美联储在长期保持利率稳定后，1994年突然提高利率，债市为之一惊，导致加州奥兰治县和其他一些债券投资者损失惨重。

For that reason alone, the Fed is going to be very loud in advance about plans to sell bonds and raise rates when the time comes.

单凭这个原因，美联储会在时机成熟时，大张旗鼓地提前放出有关售债和加息计划的风声。