美国经历过1929年的大萧条，日本经历过1989年的衰退，东南亚则经历过1997年的危机。若干年后，中国是否也将面临一个类似的灾难时刻？

这个问题不仅对于那些眼下投资亚洲的人至关重要，对于范围更大的全球市场亦是如此。因为当全球投资者步履蹒跚地走出此次金融危机之际，许多人坚信这样一个观点：中国的繁荣，是这个冰冷世界中的一线希望之光。

问题在于，历史经验表明，这种乐观看法很大程度上可能选错了对象。

金融市场有这样一种习惯：当经济迅速发展时让自身陷入狂热，结果导致灾难。这最终宣告了市场的总体无效。问题是，在经济迅速发展时期，极端乐观与流动性泛滥独特地结合在一起。

经济发展会催生非同一般的乐观情绪——特别是在中国这样的大国——这有着多方面的原因。没有什么东西能像看着经济蛋糕不断变大那样，呈现出人类的动物精神。因此，购买股票等风险资产，以表达自己对未来的乐观看法，是自然而然的事情。

问题在于，市场竞争往往会压低资本回报率，并将经济发展的成果奉予员工和消费者，而非投资者。资产价格高企促使企业过度投资，这将压低资本回报率。这正是投资者之所以往往在经济迅速发展时期战绩不佳的原因。

较低的收入基数和有利的人口统计学状况，有助于推动经济成功地增长。由于收入增加部分的高储蓄率，上述两个因素往往会造成流动性过剩。在城市化进程中，尽管生产率正从农业水平转向工业水平，但消费习惯仍然带有农村性质——也就是说，必需品之外的东西仍被视为奢侈品，并被减至最低水平。劳动生产率上升和消费偏好之间日益扩大的差距，会导致流动性过剩，从而催生泡沫。

中国的计划生育政策带来了最大的人口红利，但可能会让中国成为当代最容易产生泡沫的国家。中国地方政府的收入依赖于房地产市场，这使得形势更为严峻。每隔大约5年时间进行换届选举的地方政府官员，在活跃房地产市场、从而将地方政府收入最大化方面有着强大的动机。这种政治动机为巨大的房地产泡沫埋下了种子。

同样，中国股市仍将处于估值过高的状况，尽管在出现恐慌和暂时流动性短缺时，股市估值水平有时会有所下降。较低的资本回报率加之股价高企，意味着企业会转而通过股市、而非消费者获取利润。

然而，当企业通过股市获得利润，而不是为股市创造利润时，这就变成了一个负和游戏(negative sum game)。它需要持续不断的流动性流入作为支撑。这就是高增长和高储蓄率之所以至关重要的原因。

另一方面，这种市场实质上为资本形成提供了补贴。资本补贴会导致产能过剩和资本回报率低下。正因如此，低盈利能力、高资产价格和高经济增长率能够共存。实际上，它们也必须共存。

无疑，中国的经济发展将成为未来一二十年最为重要的经济事件。但这种半永久性的泡沫局面，使得金融投资者参与其中的难度极大。

“买入并持有”的做法根本行不通。价值投资之所以行不通，是因为价值投资者投资决策的基础，是市盈率和市净率降至某个水平之下。

中国股市从未达到过这样的水平。如果你是沃伦•巴菲特 (Warren Buffett)，那么你可以制造自己的泡沫。他去年买入了抱负远大的电动汽车制造商比亚迪(BYD)的部分股权。此后该股已上涨8倍。如果你不是沃伦• 巴菲特，那么我建议你“低吸高抛”。问题是要找出何处是高位，何处是低位。

当经济高速增长最终难以为继时，灾难就将来临。当有利的人口统计学趋势恶化，或城市化进程结束时，都可能出现这种局面。当出现上述两种情况之一、或两种情况同时出现时，流动性或储蓄不再增长。到那个时候，股市就再也得不到补贴。

中国距离最后的灾难时刻可能还有十年时间。

到那时，生于1950年至1978年婴儿潮时期的中国人中，有一半已经退休。中国的城市化速度将约为目前的一半。好的消息是，到那时，中国将成为一个发达国家。而坏消息是，到时候中国不再会有廉价资金，来支撑被高估的资产价格。谢国忠搜狐博客　http://xieguozhong.blog.sohu.com/ 

本文作者是驻上海独立经济学家、摩根士丹利亚太区前首席经济学家

译者/梁艳裳

Fortune is favouring China, but is it due for a reality check?

The United States had 1929, Japan 1989 and south-east Asia 1997. Will China face a similar moment of reckoning a few years from now?

The question is crucial, not just for those investing in Asia today but for the wider global market. For as investors around the world reel from the recent financial crisis, many have clung to the idea of a Chinese boom as the one bright spot of hope in an otherwise grim world.

The trouble is that history suggests that much of this optimism may be misplaced.

Financial markets have a way of working themselves into a frenzy during rapid economic development, which ends up leading to disaster. It is the ultimate testimony to the gross inefficiency of markets. The problem is the unique mix of extreme optimism and rampant liquidity that occurs during periods of rapid economic development.

Economic development, especially in a large country such as China, generates exceptional optimism for many reasons. Nothing brings out the animal spirits in humans like watching the economic pie expanding. And it is natural to buy risk assets such as stocks to express one's optimism over the future.

The problem is that market competition tends to depress capital returns and give the fruits of economic development to workers and consumers rather than investors. High asset prices incentivise companies to over-invest, which depresses returns on capital. This is why investors tend to do poorly during periods of rapid economic growth.

A low income base and favourable demographics help promote successful economic development. Both tend to lead to excess liquidity due to a high savings rate on incremental income growth. When a population is urbanising, even though its productivity is shifting from the agricultural to the industrial level, consumption habits remain rural – that is, anything beyond necessities is viewed as luxury and is minimised. The widening gap between the labour productivity increase and the consumption preference leads to the excess liquidity that feeds bubbles.

China's one-child policy brings the ultimate demographic dividend but probably makes the country the most bubble-prone in modern times. The situation is made worse by the revenue dependency of local governments on the property market. Local government officials, who change every five years or so, have strong incentives to juice up the property market to maximise their revenues. This political incentive sows the seed for a great property bubble.

Similarly, China's stock market will remain overvalued, although it will deflate from time to time during panics and temporary liquidity shortages. The combination of low returns on capital and high share prices means businesses turn to the stock market rather than to their customers for profit.

But when businesses make profits from, rather than for, the stock market, it becomes a negative sum game. It needs continuing liquidity inflows to sustain it. This is why high growth and a high savings rate are vital.

On the other hand, such a market essentially subsidises capital formation. The capital subsidy leads to overcapacity and low returns on capital. This is why poor profitability, high asset prices and high economic growth rates can coexist. Indeed, they must exist together.

China's economic development is undoubtedly going to be the most important economic event for the next decade or two. But the semi-permanent bubble situation makes it extremely difficult for financial investors to participate in this story.

“Buy and hold” simply won't work. Value investing doesn't work because value investors base their decisions on price/earnings ratios and price/book value ratios falling below certain levels.

Chinese stocks never get there. If you are Warren Buffett, you can create your own bubble. He recently bought a stake in BYD, an aspiring maker of electric cars. The stock has since risen eight times. If you are not Warren Buffett, I suggest “buy low, sell high”. The problem is working out what is high and what is low.

The day of reckoning will come when the high economic growth rate finally falters. This could happen either when the favourable demographic trend worsens or urbanisation ends. When either or both occurs, liquidity or savings do not grow any more. At that point, the stock market cannot be subsidised any more.

China's final day of reckoning is probably 10 years away.

By that time, half of China's babyboomers who were born between 1950 and 1978 will have retired. And the Chinese urbanisation rate will be about half what it is today. The good news is that China will be a developed country by then. The bad news is that there will be no cheap money for supporting overvalued asset prices any more.

The writer is an independent economist based in Shanghai and former chief economist for Asia-Pacific at Morgan Stanley