美国最新GDP数据揭示出了什么信息？

Economic growth
经济增长

What America’s latest GDP figures reveal
美国最新GDP数据揭示出了什么信息？

The economy is as strong as Donald Trump says—but perhaps not for long
美国经济诚如总统特朗普所说的非常强劲，但可能不会持续太久。

Aug 2nd 2018

2018年8月2日

STATISTICAL releases seldom propel presidents onto the White House lawn for press conferences. But on July 27th President Donald Trump was “thrilled” to announce that America’s economy grew by the “amazing” rate of 4.1% in the second quarter of 2018—enough to put it on track for average annual growth of over 3%. Most important, he bragged, “these numbers are very, very sustainable.”
据英国《经济学人》8月2日的消息：美国总统鲜有为统计数据而到白宫草坪上举行新闻发布会。但在7月27日，美国总统唐纳德•特朗普却“兴奋地”宣布，2018年美国第二季度经济以4.1％的“惊人”速度增长，足以确保该国经济年均增长率超过3％。他还夸口说，最重要的是，“这些数字是非常，非常可持续的。”

Championing early estimates of GDP is a risky business, because perky performance can be revised away. In this case the numbers were an advance release based on incomplete data. Between 1993 and 2016 such estimates were revised by an average of 1.3 percentage points. (Of course, what can go down can also go up.) The 4.1% growth rate that Mr Trump found so stunning was an annualised one, which compounds quarterly GDP growth assuming three more quarters of identical change. That measure is prone to being bumped around by one-off effects. The latest figures were boosted by a temporary surge in exports of “foods, feed and beverages”, as exporters of soyabeans raced to get their produce into China ahead of tariffs imposed on July 6th. Though very strong, the growth was hardly unprecedented. It was higher four times during Barack Obama’s presidency (see chart).
倡导对GDP早期评估是一项有风险的业务，原因在于良好的表现可能会消失。在本例中，数字是基于不完整数据提前发布的。从1993年到2016年，这类估算值评均修订了1.3个百分点（当然，下降的数据也可能会上升）。特朗普认为，如此惊人的4.1％的数据是一种年化的增长率，假设有三个季度的相同变化，这使得季度GDP增长更加复杂。这一措施易受短期影响所左右。最新的数据因“食品，饲料和饮料”的临时性出口激增而受到提振，而大豆出口商竞相在7月6日征税令实施前将农产品送到中国。尽管增长非常强劲，但并非史无前例。在奥巴马担任总统期间，这一数字曾高升了四倍（见图表）。

Yet the figures are not to be scoffed at. Analysts were pleasantly surprised by the composition of growth, which appeared to be fuelled by American shoppers buying cars, clothing and footwear, as well as paying for housing and health care. Using a smoother measure of growth, which compares quarterly GDP with the same quarter a year ago, the economy still grew in the second quarter by a healthy 2.8%. If growth for the year as a whole reaches 3%, as the president has boldly predicted, few forecasters would be shocked. In April the IMF forecast growth of 2.9%; the non-partisan Congressional Budget Office (CBO) went for 3.3%.
不过，这些数字不应受到不屑一顾。有分析师惊喜地发现，美国消费者购买汽车，服装，鞋类以及支付住房和医疗保健费用，这似乎助长了经济增长的构成。通过采用更平稳的增长指标来衡量季度GDP和与去年同期相比，美国第二季度经济仍健康地增长了2.8％。如果诚如特朗普总统所大胆预测的那样，美国全年经济增长率达到了3％，几乎也没有预测者会对此感到震惊。今年4月份，国际货币基金组织（IMF）预测2018年美国经济增长率为2.9％；无党派立场的美国国会预算办公室（CBO）的预测数字为3.3%。

Mr Trump’s claim that a 3% growth rate is sustainable is more dubious. The tariffs he loves to impose could blow the economy off course. Even if they do not, some part of the economy’s buoyancy is probably only temporary, and related to a cyclical upswing. Some is probably due to the recent tax cuts, which the CBO estimates will add around 0.3% to American GDP this year and 0.6% next year. Beyond that, they reckon, the positive effects will fade as bigger budget deficits crowd out private-sector investment.
特朗普声称3％的经济增长率是可持续的，这一点是令人更加质疑的。他倾向于征收关税的举措可能会致使经济偏离轨道。即使关税对经济不构成影响，某些时段的经济繁荣可能只是暂时的，并同周期性的上升相关。其中一些可能是由于最近的减税政策，美国国会预算办公室估计这将会使美国今年的GDP增长约0.3％，明年将增至0.6％。除此之外，他们认为，随着更大预算赤字对私人领域投资的排斥，这种积极的影响将会消退。

In the long run, America’s economic potential depends on how many workers it has and how productive they are. The workforce is growing more slowly than in the past, partly because the large baby-boom generation is retiring and partly because the surge of women into paid employment has run its course. Given how disappointing productivity performance has been in recent years, it is unsurprising that bodies like the CBO and the Federal Reserve seem sceptical that the American economy can sustain a real long-run growth rate far above 2%.
从长远来看，美国的经济潜力取决于该国工人的数量和生产效率。劳动力的增速比过去要慢，部分原因是大量的婴儿潮一代即将退休，另一部分原因是女性进入有偿就业的浪潮已经结束。鉴于近年来令人失望的生产率表现，美国国会预算办公室和美联储等机构似乎对美国经济能否保持远高于2％的实际长期增长率持有怀疑态度，这也是令人不足为奇的。

The president’s economic team may protest that his tax reforms should stoke investment, raising America’s economic capacity. Business investment grew by an annualised rate of 7.3% in the second quarter of 2018. That is welcome, but it cannot really be attributed to the tax package. About half of the overall rise reflected a high oil price stimulating investment in mining exploration, shafts and wells. Alternatively, critics of the Federal Reserve gripe that its gloomy forecasts have been self-fulfilling, and that America’s persistently disappointing wage and productivity growth over the past few years comes partly from monetary policymakers’ unwillingness to let the labour market roar.
美国总统的经济团队可能会抗议称，他们的税收改革会刺激投资，提升美国的经济能力。2018年第二季度企业投资按年度计算增长了7.3％。这是受欢迎的，但这不能真正归因于一系列税收改革方案。经济总体增长中的一半左右来自高油价刺激了对采矿勘探、矿井和油井的投资。另外，美联储的批评人士抱怨称，该机构的悲观预测已经在自我实现，而造成美国过去几年持续令人失望的薪资和生产率增长的部分原因是货币政策制定者不愿让劳动力市场出现混乱。

If Mr Trump is wrong, and the economy cannot sustain a growth rate of 3%, policies to try to get it there may only stoke price increases. The rate-setters at the Federal Reserve are keenly aware of this risk. On July 31st new figures revealed core inflation (excluding volatile food and energy prices) to be 1.9%, close to the 2% target. Although they held interest rates steady when they met on August 1st, two more increases are expected this year. Rate-setters fear that a burst of inflation is too close for comfort, and that if they do not squeeze the economy’s brakes slowly now, a more abrupt stop might be required later. In doing so, they are making Mr Trump’s hopes of 3% growth harder to realise. To the president, this may seem cruel. But he is not alone in the driver’s seat.
如果特朗普出错，美国经济无法维持在3％的增长率，那么试图实现这一目标的政策可能只会加剧物价上涨。美联储的利率制定者敏锐地意识到了这种风险。7月31日，新数据显示核心通胀率（不包括食品和能源价格的波动）为1.9％，接近2％的目标。尽管他们在8月1日举行会议时宣布保持利率不变，但预计今年还会有两次加息。利率制定者担心，通货膨胀的爆发正在逼近，如果他们现在还不放慢经济刹车的速度，那么晚些时候可能还会被迫更突然地停止。此举会致使特朗普3％的经济增长率的希望更难实现。对美国总统而言，这也许显得有些残酷，但并非只有他一个人如坐针毡。（译：曹亚蒙）

https://www.economist.com/united-states/2018/08/04/what-americas-latest-gdp-figures-reveal