考研时文阅读 二 选自《经济学人》

AMID the hubbub over a few less-bad-than-expected statistics, America’s economic debate has turned to the nature of the recovery. Optimists expect a vigorous rebound as confidence returns, pent-up demand is unleashed and massive government stimulus takes effect. Most observers, including this newspaper, are bracing for a long slog, as debt-laden consumers rebuild their savings, output growth remains weak and unemployment continues to rise. There is, however, something that eventually will have a much bigger impact on Americans’ prosperity than the slope of the recovery. That is the effect of the crisis on America’s potential rate of growth itself.

在对一些比预期稍好的数据的聒噪中，对美国经济的争论倒向了恢复的一边。乐观人士预计在信心回稳、抑制的需求得到释放以及政府大规模刺激方案取得成效的情况下，经济会有力的反弹。包括本报在内的多数观察家则认为慢慢前路仍充满艰险，因为深陷债务泥潭的消费者在重新建立他们的储蓄，出口增长依然疲软而且未就业人数继续上升。然而，一些东西最终对美国繁荣的影响要比经济复苏这一斜线大的多。那就是危机对美国潜在增长率的影响。

An economy’s long-term speed limit (its “trend” or “potential” rate of growth) is the pace at which GDP can expand without affecting unemployment and, hence, inflation. It is determined by growth in the supply of labour (the number of workers and how long they toil) along with the speed with which productivity improves. The pace of potential growth helps determine the sustainability of everything from public debt to the prices of shares.

一个经济体的长期速度限制（它的“趋势”或“潜在”增长率）是它维持GDP能够增长而又不影起未就业人数和通货膨胀变化的速度。它由劳动力供给（工人数量和工作时间）的增长与生产率提高的速度决定。潜在增长率的速度帮助决定了从公共债务到股票价格等的一切事物的可持续性。

Unfortunately, the outlook for America’s potential growth rate was darkening long before the financial crisis hit. The IT-induced productivity revolution, which sent potential output soaring at the end of the 1990s, has waned. More important, America’s labour supply is growing more slowly as the population ages, the share of women working has levelled off and that of students who work has fallen. Since 1991 the labour supply has risen at an average annual pace of 1.1%. Over the next decade the Congressional Budget Office expects a 0.6% annual increase.

不幸的是，早在金融危机袭来之前，美国的潜在增长率的前景就日趋暗淡。曾在90年代末使潜在前景飞涨的IT导向型生产力革命已经式微，更重要的是，美国的劳动力供给速度要远落后于人口老龄化的速度。参加工作的妇女所占的份额与之前持平，而学生的就业率在下降。自1991年起劳动力供给以年均1.1％的速度增长。国会预算办公室预测未来10年的增长速度为0.6％。

According to Robert Gordon, a productivity guru at Northwestern University, Americ a’s trend rate of growth in 2008 was only 2.5%, the lowest rate in its history, and well below the 3-3.5% that many took for granted a few years ago. Without factoring in the financial crisis, Mr Gordon expects potential growth to fall to 2.35% over the coming years.

据西北大学生产力专家Robert Gordon,称，美国2008年的增长率仅仅接近2.5％，这是历史上的最低点，而且远低于多数人前些年认为理应达到的3－3.5％。将金融危机排除后，Gordon先生预计未来几年