美国国债:收益率2009-06-03Buttonwood布雷顿森林体系Not so risk-free并非那么无风险May 28th 2009From The Economist print editionThere are questions about the long-term appeal ofAmerican Treasury bonds美国国债的长期表现令人怀疑LIKE London buses, big events in America’s Treasury market all seem to come at once. In a week when the Treasury auctioned more than $100 billion of notes and bonds, ten-year Treasury yields surged to their highest level in six months, despite a buy-back offer by the Federal Reserve. That will raise the cost offinance for companies and homeowners.就像伦敦巴士一样，美国债券市场的大事件都是毫无预兆就发生的。
在一周之内，财政部拍卖了多达1000亿美元的债权，尽管联储回购了一部分，十年期国库券的收益率一路飙升到6个月以来的最高点。
这会加重公司和家庭的财务成本。
All this activity was inevitable once the authorities decided to combine a huge fiscal deficit with quantitative easing (expansion of the money supply). It has been accompanied by a sharp rise in the gap between short and long rates. The ten-year yield has risen from 2.08% on December 18th to 3.70% on May 27th.一旦当权者决定将巨额的财政赤字和数量性政策（货币供给增加）相结合的时候，所有的这些行为都是不可避免的。
伴随着债券发放而来的长短期利率之间的差距大幅增加。
十年期债券的收益从12月18号的2.08%上涨到了5月27号的3.70%。
Some of that rise in yields is undoubtedly due to investors switching back into shares on hopes that the global recession might end next year. But there have also been concerns about America’s long-term financial health. On May 27th Moody’s said it had no plans to reduce America’s coveted AAA debt rating. But on the same day John Taylor, a professor at Stanford University a nd the creator of the Taylor rule on monetary policy, wrote in the Financial Times that the American government “is now the most serious source of systemic risk.”收益率上涨的从某种程度上说是令人猝不及防的，因为投资者在寄希望于全球大萧条会在明年年底结束的基础上将投资转回了股票市场。
但是同样也存在着对美国长期财政健康度的担心。
5月27号，Mood y’s称他们还没有将美国的AAA级评级下调的计划。
在同一天，身为斯坦福大学教授同时也是货币政策上泰勒定律创建者的John Taylor在财经周刊上撰文称：美国政府现在处在最严重的系统风险的萌芽阶段。
On the surface, the worries seem odd. Is America likely to default on its obligations? No. To put it another way, if the world ever got into a state where America did prove unable to pay, lots of other assets would have defaulted first. Even though the American budget position is deteriorating rapidly, it is still a lot healthier than that of either Italy or Japan. Both countries have been carrying debt/GDP ratios of more than 100% for years without suffering a meltdown.从表面来看，这种担心让人觉得可笑。
美国有可能会不履行自己的责任吗？不会的，从另外一个角度看，如果世界陷入了一种连美国都被证实如法偿还债务的境地的话，会有大量的资产在此之前就首先被拖欠了。
尽管美国的债务情况在逐渐恶化，但他仍然要比意大利或是日本的债务状况健康的多。
几年来，意大利和日本的债务– GDP比率都维持在大于100%的水平却没有彻底垮台。
Governm ent bonds are generally regarded as risk-free in their home countries, because the government has the power to tax and to print money. Since America is the world’s largest economy, has the most liquid financial markets and operates the world’s premier reserve cur rency, the Treasury bond has been seen as the global risk-free asset.通常政府债券在本国内被认为是无风险的，因为政府掌握着征税和印制钞票的权利。
自从美国成为世界最大的经济体，拥有着流动性最强的金融市场以及操控着世界首要储备货币以来，美国国库券被认为是全球最无风险的资产。
But that status implicitly rests on the belief that the American government will not exploit its advantages to the full. The same fiscal and monetary policies that seem appealing as a way of addressing domestic economic weakness also reduce the appeal of its debt to foreign investors.但是这种情况潜在的基础是一种对美国政府不会把自身的优势消耗殆尽的信赖。
在拉动国内经济走出低迷方面具有吸引力的财政和货币政策同样也削减了其债权对国外投资者的吸引力。
America does not formally need to default to penalise its creditors; it can simply let its currency decline. Short-dated Treasury bonds (those with a maturity of one-to-three years) have returned a healthy 18% in dollar terms over the last three years. But when translated into Chinese yuan that return dwindles to just 0.3%.从形式上看美国没必要用违约的方式来惩罚借贷方，只要很简单的将美元贬值就可以了。
在过去三年里，用美元计价的短期国库券（期限为1-3年的债券）健康程度恢复到了18%，但是兑换成人民币之后这种健康程度的恢复减少到了只有0.3%。
History is full of examples of sovereign nations failing to pay their overseas creditors in full. When push comes to shove, governments are unwilling to impose the required level of austerity on their voters. This happened in the 1920s Weimar Republic, which opted for hyperinflation rather than paying the reparations bill, and in 1930s Britain, which abandoned the gold standard in the face of the Depression. (Note the results of the recent referendums in California, where voters rejected all budget-balancing proposals.)历史上有太多这样的例子：主权货币国家沦落到要全额支付其海外借贷方的地步。
当努力争取变成强制要求时，政府不愿意将这种节衣缩食强加到他们的选民身上。
这样的事情发生在20世纪20年代的魏玛共和国，他们选择了超级通货膨胀而不是支付赔款账单，同样的例子是20世纪30年代在面对大萧条时弃用了金本位制的英国，（请注意一下最近在加利福尼亚进行的全民投票，选民否决了赤字平衡的计划）In countries that are frequent offenders, including those in Latin America, foreign creditors have in the past demanded that government debt be denominated in a foreign currency. America has been able to borrow in dollars. However, for foreign investors, that means Treasury bonds are not risk-free at all.在包括拉丁美洲国家这样经常出问题的国家里，国外债权人过去的做法是要求政府债券以外币标价。