【英语国际】美国长期国债保持低收益率合理

Going long still looks the right play for Tim Geithner, but some of his Wall Street coaches are recommending a different approach.

Two years ago, heavy short-term debt issuance drove the average maturity of outstanding U.S. Treasurys to a 26-year low of 49 months. As stimulus and bailout spending has rolled off, so too has the need for short-term cash, sending the average maturity back to 58 months. The Treasury expects it to extend further, minutes of Tuesday's Borrowing Advisory Committee meeting show, but at 'a slower pace.'

That is unfortunate. While Treasury's debt-management office can't control how much it has to borrow, it can control how the debt is financed. Dire budgetary forecasts because of Medicare and Social Security commitments mean fiscal concerns won't soon recede. The risk is that, when huge slugs of debt must be rolled over, bond vigilantes one day push up borrowing costs.

FTN Financial estimates that, excluding short-term bills, $1.2 trillion of debt will have to be rolled in 2012. That would be a record, and nearly double last year's amount. Pushing out debt maturities would reduce supply that will have to come to market in the next few years.

The borrowing committee still recommends the Treasury increase the average maturity, but given progress thus far, some members say that, now with borrowing requirements falling from their peaks, it makes sense to reduce issuance across the curve.

This could prove clever. Continued weakness may push rates even lower. After all, yields on Japan's 10-year government bonds dropped below 1% this week, the lowest in seven years. Yields on similar Treasuries have fallen below 3%, but nearly touched 2% in the depths of the crisis. So they could go lower. And if bond vigilantes haven't hit Japan, despite a debt-to-gross-domestic-product ratio nearing 200%, they are arguably a way off attacking the U.S., with a ratio of 60%. Trouble is, 50% of America's debt is held by foreigners. For Japan, it's just 5%. Now, the Treasury has foreign lenders' support, but to keep them on its side it must show it won't let the deficit run out of control.

Staying at the short end of the curve also makes Ben Bernanke's job more difficult. A new asset bubble or a strong recovery may eventually force him to raise rates or shrink the Federal Reserve's balance sheet. Would that be tougher if the Treasury were still flooding the market with paper?

The U.K. pays more, on a weighted-average basis, than the U.S. for its debt. But its conservatism, with an average maturity over 13 years, could give it more margin for error. Unless the Treasury believes the U.S. is going the way of Japan, locking in low long-term rates still makes sense.

对美国财政部长盖特纳来说，做多不失为一个好办法，但是部分华尔街的金融指导师们开始向他推荐一个不同的方法。

两年前，大量的短期债务发行使美国国债平均到期年限达到49个月，为26年以来的低点。随着经济刺激和救市支出的大量增加，短期资金的需求也随之减少，使平均到期年限回到了58个月。周二，美国国债借款咨询委员会的会议纪要显示，财政部预期这一期限会继续延长，但速度会稍慢一些。

这很不幸，尽管美国财政部债务管理办公室管不了要借多少钱，但是能够控制如何筹措这些债务。联邦医疗保险和社会保险的费用使财政预算的预测数字高企，这意味着对财政赤字的担忧不会很快降低，风险是当巨额债务必须在市场上延期，债市警卫们（bond vigilantes）有一天会推高借贷成本。

FTN金融公司预测，不包括短期国债，12万亿美元债务将会在2012年延期。那将会是个创记录的数字，几乎是去年的两倍。延长债务到期期限会减少未来几年的市场供给。

借贷委员会仍然建议提高国债平均到期年限，但到目前为止，一些成员表示，现在随着借贷条件降低，减少发行是合理的。

可以证明这是明智的做法。经济持续走弱可能会推低利率。毕竟，日本10年期政府债券收益率本周跌至1%以下，为七年来最低点。类似的债券收益率跌至3%以下，但在危机中曾接近2%，因此收益率可能会跌得更低。日本债务和GDP的比率接近200%，而债市警卫尚未冲击日本，美国的债务和GDP的比率为60%，所以受到类似冲击的可能性也许较小。问题是，50%的美国国债由外国人持有，而日本国债中仅有5%被外国人持有。现在，美国国债有外国借贷者的支持，但是想留住他们必须证明赤字不会失去控制。

处在收益率曲线的低端也让贝南克的工作变得更加困难。新的资产泡沫或强劲的经济复苏最终可能会促使他提高利率或缩减美联储的资产负债表。如果财政部依然往市场里注入大量货币，难道不是雪上加霜吗？

以加权平均值来看，与美国相比，英国的国债收益率较高。但由于英国的保守主义和国债平均到期年限超过13年，可以给错误决策留有更多缓冲余地。除非财政部认为美国应遵循日本的方式，把长期利率维持在低水平仍然是合理的。