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When will China overtake America?
中国经济何时超越美国？

Dec 16th 2010 | from PRINT EDITION

FORGET Monopoly or World of Warcraft. The Economist’s idea of Christmas fun is guessing when China’s economy will leapfrog America’s to become the world’s biggest. The Conference Board, a business-research group, recently predicted that China could become the world’s largest economy as soon as 2012 on a purchasing-power-parity (PPP) basis, which adjusts for the fact that prices are lower in China. But economists disagree on how to measure PPP. And America will only really be eclipsed when China’s GDP outstrips it in plain dollar terms, converted at market exchange rates.

忘了“地产大亨”或“魔兽世界”这些电脑游戏吧。《经济学人》网站推出的圣诞娱乐项目是猜测中国经济何时超越美国，成为世界第一经济大国。世界大型企业联合会（Conference Board）是一个企业研究机构，据该机构最近的预测，中国到2012年就可能成为世界上最大的经济体，当然这是以购买力平价（PPP）为基础进行的估算，是考虑到中国的物价较低的事实而做出了调整的结果。但在如何确定购买力平价的问题上经济学家们各持己见。中国只有在以按市场汇率兑换的美元来计算，其GDP也超过了美国时，美国才算真正黯然失色。

Since by that reckoning China’s GDP is currently only two-fifths the size of America’s, that day may still seem distant. But it is getting closer. When Goldman Sachs made its first forecasts for the BRIC economies (Brazil, Russia, India and China) in 2003, it predicted that China would overtake America in 2041. Now it says 2027. In November Standard Chartered forecast that it will happen by 2020. This partly reflects the impact of the financial crisis. In the third quarter of 2010 America’s real GDP was still below its level in December 2007; China’s GDP grew by 28% over the same period.

按这种方式计算，中国目前的GDP只是美国的2/5，赶超美国的日子可能仍然十分遥远。但这一天是愈来愈近了。高盛（Goldman Sachs ）2003年第一次为金砖四国（巴西、俄罗斯、印度和中国）的经济发展做出预测时，它预计中国可能在2041年超越美国。现在它预测这一赶超的年份可能提前到2027年。而渣打（Standard Chartered ）在今年十一月预测，这一赶超年份可能是2020年。这个预测部分反映了金融危机的影响。2010年第三季度美国的实际国内生产总值仍低于2007年12月的水平，而同期中国的GDP增长了28％。

If real GDP in China and America continued to grow at the same annual average pace as over the past ten years (10.5% and 1.7% respectively) and nothing else changed, China’s GDP would overtake America’s in 2022. But crude extrapolation of the past is a poor predictor of the future: recall the forecasts in the mid-1980s that Japan was set to become the world’s largest economy. China’s growth rate is bound to slow in coming years as its working-age population starts to shrink and productivity growth declines.

如果中国与美国的实际国内生产总值每年都继续以过去十年同样的年平均速度增长（分别为10.5％和1.7％），而其他因素都不变化，则中国的GDP将在2022年超越美国。但以过去的数字去粗略地推断未来的情况，预测效果往往很不准确。想想上世纪80年代中期的预测，当时都认为日本将成为世界上最大的经济体。由于中国工作年龄人口数量开始萎缩与生产率增长的下降，中国经济的增长速度在未来的年份里必将放慢。



Then again, the relative paths of dollar GDP in China and America depend not only on real growth rates but also on inflation and the yuan’s exchange rate against the dollar. In an emerging economy with rapid productivity growth the real exchange rate should rise over time, through either higher inflation or a rise in the nominal exchange rate. Over the past decade annual inflation (as measured by the GDP deflator) has averaged 3.8% in China against 2.2% in America. And since China ditched its strict dollar peg in 2005 the yuan has risen by an annual average of 4.2%.

再说，在中国和美国以美元计算的国内生产总值的相对路径不仅取决于实际增长率，也取决于通货膨胀率和人民币与美元间的汇率。在一个生产率迅速增长的新兴经济体国内，其实际汇率也会随着时间的推移而上升，方式则可能要么通过高通货膨胀率，要么就是名义汇率的上升。在过去十年中中国与美国的年通胀率（按GDP平减指数衡量）平均是3.8％对2.2％。此外，由于中国在2005年抛弃了其严格与美元挂钩的汇率政策，人民币的年平均升值幅度达到了4.2％。

The Economist has created an online chart (www.economist.com/chinavusa) that allows you to plug in your own assumptions about future growth, inflation and the exchange rate. Our best guess is that annual real GDP growth over the next decade averages 7.75% in China and 2.5% in America, inflation rates average 4% and 1.5%, and the yuan appreciates by 3% a year. If so, then China would overtake America in 2019 (see chart). If you disagree and think China’s real growth rate will slow to an annual average of only 5%, then (leaving the other assumptions unchanged) China would have to wait until 2022 to become number one. Americans would still be much richer, of course, with a GDP per head more than four times that in China. But don’t expect that to dampen Chinese celebrations, whenever they come.

《经济学人》网站 设置了一个在线图表（ www.economist.com / chinavusa ），你可以在图表中插入你自己假设的未来的GDP增长率、汇率及通货膨胀率数字。本网站猜测的数字分别是：中国与美国在未来十年内年平均GDP增长率分别为7.75％与2.5％，通胀率分别为4％与1.5％，人民币升值的速度为每年3％。如果本网站猜测正确，则中国经济总量将在2019年超越美国（见图表）。如果您不同意我们的猜测，认为中国GDP的实际增长速度将放缓到只有5％的年平均水平，则（假设其他因素不变）中国经济总量将不得不等到2022年才能成为世界第一。当然，即使到了那时美国人也仍然要富得多，因为那时美国的人均GDP仍然是中国的四倍多。但不要指望这个数字会给中国人泼冷水。无论这一天什么时候到来，中国人都会兴高彩列地庆祝一番。