【编按】曾经担任美国克林顿政府国家安全委员会欧洲事务主任的查尔斯.库普乾(Charles Kupchan)说过，共和党政府相当封闭，「通常他们一旦形成了某种看法，就会径直去推行；就算要征求外界意见的话，他们也只会找一个观点与之相同的」。最近，因为奥巴马在《新共和》杂志读了《世界美国造》一书的节选，而受到追捧的该书作者罗伯特·卡根（Rbert Kagan）迅速的成为美国右派的指标人物。去年2月美国哥伦比亚大学教授杰弗里.萨克斯(Jeffrey D. Sachs)在金融时报与罗伯特·卡根发生一场小小的书信笔战，后来罗伯特·卡根的辩解是「IMF自身的数据是经常变动的」、「它们也经常把这些数据调高或调低」。无论遭受如何重大的质疑，罗伯特·卡根仍不愧是美国单极超强大国的「封闭铁杆」。以下是萨克斯与卡根两人「书信笔战」的资料存查。
Letters：If this isn’t a world-altering economic shift, then what is?
作者：Jeffrey D. Sachs 2012年2月9日 financial times
Sir, Robert Kagan (Letters, February 7) denies a “world-altering shift in economic weight”
in the shares of world income reported by the International Monetary Fund. He should
look again.
In 1980, the US share of world income (measured in purchasing power parity prices) was
24.6 per cent. In 2011, it was 19.1 per cent. The IMF projects that it will
decline to 17.6 per cent as of 2016.
China, by contrast, was a mere 2.2 percent of world income in 1980, rising to
14.4 per cent in 2011, and projected by the IMF to overtake the US by 2016, with 18 per cent.
If this isn’t a world-altering shift, it’s hard to imagine what would be.
Jeffrey D. Sachs, Director, Earth Institute, Columbia University, NY, US
Letters：US share is still about a quarter of global GDP
Mr Luce cites as his source the International Monetary Fund’s World Economic Outlook. However, even according to that database (which can be found at www.econstats.com/weo/V012.htm ), the US share of global GDP, measured in purchasing power parity, was a little over 24 per cent in 1980 (the database does not go back farther), a little over 23 per cent in 2000, and a little over 21 per cent prior to the recession that began in 2008. This is not a world-altering shift in economic weight.
But even if Mr Luce’s numbers were the only measure out there, it is simplistic to judge the distribution of power in the international system entirely on the basis of the size of a nation’s economy. China’s economy was also the largest in the world in 1800. Mr Luce does not address such complicating matters as the fact that China’s per capita GDP is a small fraction of that of the US.
There is a far more sophisticated argument for China’s growing economic power, presented by Arvind Subramanian in his book Eclipse, which I acknowledge and address in my book.
China’s challenges greater than US’s
Sir, Two points in response to Jeffrey Sachs (Letters, February 9).
First, according to the International Monetary FundWorld Economic Outlook report of 2010, the US share of world gross domestic product based on purchasing power parity in 1980 was 22.499 per cent. In 2007, the last year before the Great Recession, the US share was 21.289 per cent. So any world-altering shifts, at least on the economic front, would have to have occurred only in the past four years. Although I am not an economist, I would argue that basing projections about the future distribution of economic power during a deep American recession is hazardous. (By the way, I note that the IMF’s figures about global share of GDP, both in the future and even in the past, are constantly being revised upwards and downwards.)
Second, and more important, as I noted in myresponse to Edward Luce(Letters, February 7), share of global GDP is an inadequate measure of a nation’s geopolitical position – which is the subject of my bookThe World America Made. There is no question that China’s relative economic influence is increasing as its share of the global economy increases, but that is only one aspect of power. There are ways in which its political and strategic influence has notably declined over the past couple of years – witness the regional unity against Chinese actions in the South China Sea.
As a general matter, China’s strategic challenges are far more difficult than those faced by the US. So I remain unconvinced that the rise of China’s share of global GDP alone is of world-altering significance.
