中國經濟能否打破物極必反的歷史規律

There has been plenty of discussion lately about signs that China’s economy is slowing down, focused on details of a possible housing bubble and vast sums of bad loans that the country will have to reckon with. But put aside the challenges China faces this quarter, or next year, and there is one view that is overwhelming: China is a long-term economic juggernaut that will stand astride the global economy in another generation’s time.

最近，人們關於中國經濟正在放緩的跡象有諸多談論，討論的焦點主要是潛在的房地產泡沫以及中國不得不面對的大量壞賬等細節。但是，拋開中國本季度或明年面臨的挑戰不論，這裏有個非常驚人的觀點：長遠來看，中國是個經濟大國，再過一代人的時間，它就會成爲世界經濟的領軍者。

I know this because, for years now, major magazines and editorials and books have told me about the Chinese Century, in which we are apparently now living. Leading foreign policy journals have devoted copious ink to exploring what China’s rise will mean for global economics and politics, often taking as a given that China will be the dominant power of the coming century. (“Can the Liberal System Survive?” Foreign Affairs asked in 2008.)

我知道這一點是因爲，數年來，重要雜誌、社論文章和書籍都在向我講述“中國世紀”(Chinese Century)，我們現在明顯就生存在這樣一個世紀。主要的外國政策雜誌用大量筆墨探索了中國的崛起對於國際經濟和政治意味着什麼——人們往往認爲，中國將成爲即將到來的這個世紀的主宰力量。（“自由體制能繼續下去嗎？”《外交》(Foreign Affairs)雜誌2008年問道。）

Official forecasts — from international agencies like the Organization for Economic Cooperation and Development and the World Bank, and from United States intelligence circles — envision China continuing to grow rapidly over the next couple of decades, its economy eventually becoming much larger than that of the United States. Robert W. Fogel, a Nobel laureate in economics, forecast in 2010 that in 2040, Chinese economic output would be $123 trillion, about seven times the current size of the American economy (and three times his forecast for the United States in 2040).

官方的預測——來自經濟合作與發展組織（Organization for Economic Cooperation and Development，簡稱OECD）、世界銀行(World Bank)等國際機構，以及美國情報圈——認爲未來數十年，中國經濟將持續快速增長，其經濟總量最終將遠遠超過美國。諾貝爾經濟學獎得主羅伯特·W·福格爾(Robert W. Fogel)2010年預測，到2040年，中國經濟產量將達到123萬億，約爲美國當前經濟總量的7倍（約爲他對美國2040年經濟總量預測值的3倍）。

But what if it’s all hogwash?

不過，如果這些都是胡扯呢？

Many of the most bullish forecasts of China’s economic future are based, more or less, on extrapolation. For more than three decades, its economic output per person has been rising at an extraordinary annual rate of 6 to 10 percent, climbing rapidly toward levels in the richest nations. If that continues for a couple of decades, the bullish forecasts will prove accurate.

許多對中國經濟最樂觀的看法都或多或少地建立在推論之上。30餘年來，中國的人均經濟產出一直在以6%至10%的速度增加，中國正在迅速追趕世界最富裕國家的水平。如果這種趨勢再持續數十年，事實就會證明，這種看漲的預測是準確的。

But if you look at the long arc of economic history, such performance would be a remarkable aberration. That’s the argument that the Harvard economists Lant Pritchett and Lawrence H. Summers make in a new working paper. In short, past performance does not predict future results. What tends to happen, rather, is “reversion to the mean”: Countries having long periods of abnormal growth tend to revert to something around 2 percent growth, closer to the long-term global average.

但是，如果看看經濟歷史的長期走勢，就會知道這種表現是一種罕見的反常現象。哈佛大學(Harvard)經濟學家蘭特·普里切特(Lant Pritchett)和勞倫斯·H·薩默斯(Lawrence H. Summers)在一篇新工作文件中表達的就是這個觀點。簡而言之，不能用過去的表現來預測將來的結果。相反，可能發生的情況是“迴歸均值”：那些經濟長期以反常速度增長的國家很可能會回到2%左右的增長速度，接近長期的國際平均值。

“China’s experience from 1977 to 2010 already holds the distinction of being the only instance, quite possibly in the history of mankind,” with sustained super-rapid growth for more than 32 years, they write. “Why will growth slow? Mainly, because that is what rapid growth does.”

“中國從1977年到2010年的獨特經歷已經使之成爲特例，很可能在人類歷史中都是如此，”他們在提及中國在逾32年的時間裏都維持着極高的增長速度時寫道。“爲什麼增長速度會放慢？主要是因爲，快速增長就是會這樣的。”

There are plenty of other China pessimists out there, who note everything from aging demographics to years of politically driven investment that may offer poor returns, to an economy trying to make the perilous transition away from investment spending and toward consumers. Just last week, a Conference Board report argued that China’s economy would slow as a credit and investment bubble deflated.

對中國持消極態度的仍然大有人在，這些人提出了許多理由，從人口老齡化，到基於政治的投資——這種投資的回報可能不高，再到這個經濟體正試圖做出從投資支出到依賴消費者的危險轉變。上週，世界大型企業聯合會(Conference Board)的一篇報告指出，中國的經濟必然會放緩，投資泡沫也會破裂。

But part of what makes the argument from Mr. Pritchett and Mr. Summers interesting is that they don’t trouble themselves with those gory details of why growth may slow; they say just that the historical evidence suggests it is likely. Maybe concerns about debt levels and bad investments in China will prove justified. Or maybe not. Regardless, we should think that a change is more likely than not.

但是，讓普里切特和薩默斯的論點顯得頗爲有趣的部分內容是，他們並沒有大費周章地去考慮導致增速放緩的殘酷細節，只是說歷史證據表明這種情況很可能會發生。或許事實最後會證明，人們對於中國債務水平和不良投資的擔心是合理的。不過事情或許並不會這樣。不論如何，我們都應該認爲，改變是很可能發生的。

“China is a huge economy and a profoundly different economy than it was a generation ago,” Mr. Summers, the former Treasury secretary, said in an interview. “But it would be ahistoric to extrapolate and assume with any high degree of confidence that China will enjoy such extraordinary growth rates over the long term. Economists, strategic analysts, business planners and nervous neighbors should all recognize that a very wide spectrum of economic outcomes is possible over the next generation and that the most likely outcomes involve a very substantial slowing of growth.”

“中國是一個巨大的經濟體，與它二三十年之前的情況已經完全不同，”前財政部長薩默斯在一次採訪中說。“但是，帶着高度信心來推斷和假設中國將長期享受這種超常增長速度，就是脫離歷史語境了。經濟學家、策略分析師、業務策劃師，以及情緒緊張的鄰國都應該認識到，未來二三十年，它的經濟產出可能會落入一個非常寬的區間，而最有可能的的情況，是它的增速會大幅放緩。”

The paper’s authors put it in baseball terms. “If a hitter has a hot streak with a batting average up 50 points over the past 20 at-bats, then we would forecast a return to the average batting average over the next 20 at-bats,” they write. “If pressed to say why the batting average would be lower, one could speculate about why it currently is so high and predict those factors will diminish or predict future events will causally explain the lowering, but mainly, this is just what happens.”

該文作者用棒球術語做比喻。“如果一個擊球手，在之前的20個打數中連續得分，安打率高達5成，那麼我們預計，在未來的20個打數中，他會迴歸到平均的安打率水平，”他們寫道。“如果必須說說爲什麼安打率會降低，你可以思考一下，爲什麼它現在如此之高，並預測一下，這些因素減少會出現什麼情況，或者預測一下，未來會發生哪些事件，導致安打率降低，但關鍵是，事情就是這個樣子。”

The strongest arguments that they may be wrong, by contrast, focus on details of why China (as well as India, which they also analyze) has the potential to keep growing rapidly for many years to come.

相較之下，最有力的的反方論點側重在爲什麼中國（以及另一個分析對象印度）有可能在未來的年頭裏繼續保持快速增長。

I asked Jim O’Neill, the former Goldman Sachs strategist who coined the term “BRIC” for the large emerging economies of Brazil, Russia, India and China, to critique the Pritchett-Summers paper.

吉姆·奧尼爾(Jim O’Neill)是前高盛(Goldman Sachs)分析師，把巴西、俄羅斯、印度和中國這四個大型新興經濟體稱爲“金磚四國”的人就是他。我請奧尼爾談談對普里切特和薩默斯的文章的看法。

“In the case of China and India, the core driver of why a more positive path is likely to continue is the simple process of urbanization,” Mr. O’Neill wrote in an email. “If and when each get close to 70 percent urbanized, I’d have more sympathy with their findings, but this is a long way off.” (Just more than half of Chinese and a third of Indians live in cities. When people move from rural areas to cities, their economic output tends to rise sharply).

“中國和印度未來的道路可能仍然會比較順暢，其核心驅動力其實就是城市化進程，”奧尼爾在電子郵件中寫道。“如果城市化程度接近了70%，我會更加認同他倆的研究結果，但那是很久以後的事了。”（中國城市居民的數量略微高出總人口的一半，印度城市居民佔三分之一。當人們從農村搬到城市時，國家的經濟總量往往會大幅增加）。

In other words, a China bull can look at the details of the country’s situation — the great potential of its people to keep increasing their productivity, a political system that has proved resilient through the challenges of the last few decades — and see plenty of reasons for optimism. The reversion-to-the-mean view says simply, “We don’t know what will go wrong, but history suggests that something will.”

換句話說，中國的牛市有細節支持——中國人具有提高生產力的巨大潛力，而且事實證明，中國的政治體制富有彈性，過去幾十年的挑戰並沒有把它壓倒——有很多理由說明，我們應該保持樂觀。“迴歸均值”的觀點無非是在說，“我們不知道會出什麼問題，但歷史表明，總會有些事出問題。”

If the pessimistic view is right, there are enormous implications for the global economy’s future. If China’s per capita G.D.P. kept growing from now until 2033 at the same rate as it has in recent decades, the country’s annual economic output would rise by $51.1 trillion over current levels in present-day dollars. By contrast, if growth reverts to the mean, the size of the Chinese economy will have increased only $11.2 trillion by 2033, or a difference of about $40 trillion. To put that in context, the current gross domestic product of the United States is about $17 trillion.

如果這種悲觀的看法是正確的，全球經濟的前景就會大不相同。如果從現在起至2033年，中國的人均GDP能保持和過去幾十年一樣的增速，那麼以美元現值計算，屆時中國的年經濟產出就會比現在高出51.1萬億美元。而如果增速恢復到均值，到2033年，中國經濟的規模將增加11.2萬億美元。兩者相差40萬億美元。作爲參考，美國目前的GDP約爲17萬億美元。

For decades, economists have been building models to try to understand the mysteries of what drives growth. Is economic destiny shaped by culture? By government institutions? By patterns of industrialization?

幾十年來，經濟學家建立了各種模型，希望得出驅動經濟增長的祕訣。經濟前景是由文化決定的嗎？還是由政府機構？還是工業化的模式？

But those debates have been inconclusive. Consider some of the economic success stories of the last generation — China, India, Mexico, Poland, South Korea and Turkey, to name a few. All have different cultures, government institutions and economic development strategies.

但是，這些爭論一直沒有定論。想一想這二三十年來的經濟成功例子——中國、印度、墨西哥、波蘭、韓國和土耳其等等。它們的文化、政府機構和經濟發展戰略各不相同。

Years of work on growth theory suggest that there is no secret recipe for a developing nation to achieve prosperity. As it turns out, a simplistic reversion-to-the-mean approach explains economic growth about as well as some more complex approaches to predicting which countries’ economies are poised to boom or shrink.

在增長理論方面進行的多年研究表明，發展中國家實現繁榮沒有固定的祕訣。事實證明，用過分簡單化的“迴歸平均值”方法來解釋經濟增長，就像用一些更復雜的方法來預測哪個國家的經濟有望繁榮或衰退一樣，都不太準確。

This work also offers a reminder: If you just extrapolate from the recent past to predict the economic future, you are likely to be wrong. Analysts predicted that the Soviet economy would soon surpass the American economy in the 1960s, that Japan’s would do the same in the 1980s and that the United States had achieved a new era of perpetual speedy growth in the late 1990s. None of these have come to pass.

這項研究還提醒我們：如果你僅僅根據近期狀況來預測未來經濟走向，你的預測很可能是錯的。20世紀60年代，分析師預測蘇聯經濟將很快超過美國經濟，20世紀80年代，他們又預測日本的經濟將很快超過美國，上世紀90年代末，他們預測美國已經進入了永久快速增長的新時代。這些都預測錯了。

In other words, when it comes to predicting nations’ fates over the long haul, we know a lot less than we like to admit.

換句話說，在預測國家的遠景時，我們所知道的東西，遠比我們願意承認的少。