（外脑精华·北京）本文指出了一种历史定式：二战以来，夏季奥运会举办国的经济增长往往会在奥运会次年受到影响。那么，中国能否打破这种持续了50年的历史定式？尤其是在当前的独特背景之下――美国的经济低迷有可能更加持久。而且，就在奥运火炬熄灭之时，加息和人民币升值的滞后效应恰恰会开始对中国经济产生影响。
本文关注的焦点有两方面：资本支出周期，以及奥运会对经济情绪产生的难以度量而又变化无常的效应。可能影响到今后几年中国经济走势的因素有很多，但我们把其他因素排除在外，以便突出在资本周期的运行过程中，奥运会这项一次性事件的影响。
奥运经济的历史定式：会后经济减速
考察1956年以来奥运会举办国的经济表现，可以发现一个惊人的共同点：奥运会当年，举办国的GDP会加速增长，而次年的GDP增速却会低于正常水平。在1956年以来的11届奥运会之中，只有举办1996年亚特兰大奥运会的美国未在会后出现经济减速。澳大利亚（1956年奥运会）、日本（1964年）、美国（1984年）和韩国（1988年）的减速尤其明显。西班牙（1992年）甚至在1993年陷入了衰退。就最近两次奥运会而言，希腊和澳大利亚在奥运会前后两年的减速幅度达到了1.5－2.0个百分点。
我们分析了历届奥运会前后的10个季度之中，举办国的经济增长、工业生产增长和投资增长三项指标相对于该时期相应指标平均水平的变化情况。GDP增长方面，在奥运会前一年，GDP增速比平均水平高1.1个百分点，奥运会当年高0.9个百分点，次年则比平均水平低1.2个百分点。投资增长的减速趋势更加明显：会前的投资增速比平均水平高3.3%，会后则比平均水平低接近7%，前后波动幅度高达10个百分点。此外，就时间关系而言，可以直观地看出，投资带动了奥运会前后的经济上升和下滑周期。工业生产方面也存在类似的起伏，其波动幅度介于GDP和投资增长之间。
上述奥运会前后经济走势的特点应该不难理解。奥运会之前，举办国自然会进行大规模投资，尤其是在非住宅建设和旅馆建设领域。而且，奥运会当年的旅游业收入也会出现大幅增长。就北京而言，通过奥运会赢得威望或许也是一个重要因素，因为中国力图借此展示其经济和国家形象，而这种做法要花费金钱，并会反映在GDP之中。奥运会之前的基础设施和其他实物投资自然意味着会后的经济减速。另一个重要因素在于，奥运会可能会对经济情绪产生积极影响，对与奥运会或举办城市没有直接关系的消费和企业投资也可能起到刺激作用。奥运会过后，随着热情的下降和注意力的转移，经济情绪可能会降温。
奥运的汇率效应：举办国大多在会后出现货币贬值
我们还分析了奥运会举办国的货币走势。这里存在一个问题：1971年之前，大多数货币都与美元和黄金挂钩，经济承受的压力无法表现在汇率上。因此，我们只讨论1972年之后的情况。
在加拿大（1972年奥运会）、美国（1984年）和西班牙（1992年），举办国的货币都在奥运会过后的两年之中大幅贬值。而在澳大利亚（2000年），澳元则在奥运次年小幅贬值。韩国（1988年）和希腊（2004）年属于另一种情况：奥运过后的两年中，美元－韩元和欧元－美元汇率都大体保持稳定。1996年亚特兰大奥运会之后，美元则有所升值。综上所述，除了少数例外情况，奥运会过后，举办国的货币会随着其经济的减速而贬值。
奥运会对中国经济和人民币的影响
那么，2008年奥运会将对中国的经济增长和人民币产生什么影响？关于这个问题，很难做出精确的回答。主要原因在于，奥运会对中国的经济活动和人民币价值既有直接影响，也有间接影响。下面指出一些重要问题：
首先，中国是大国。奥运举办国的经济规模很重要，因为只有奥运会举办城市的投资才会出现大幅波动。对美国和中国这样的大国来说，亚特兰大或北京举办奥运会对本国经济的影响不会像首尔、巴塞罗那或悉尼那样严重。因此我们认为，北京奥运会结束后，中国资本支出收缩的幅度将小于历史平均水平。1984年洛杉矶奥运会过后，美国GDP减速的幅度微乎其微；而在1996年亚特兰大奥运会之后，美国的经济增长还有所加快。原因很简单：对一个大国而言，一个城市的经济事件不足以左右全国的GDP走势。
其次，中国是多样化的国家。无论在政治上、经济上还是地理上，中国都不是一个单一性的国家。例如，中国可以划分为东部（即沿海地区）、中部和西部三大区域。而在三大区域之间，经济发展和基础设施建设水平呈突出的梯级式分布格局。鉴于此，即使美国市场的负面需求冲击打击了东部经济，中部和西部的基础设施及其他投资需求仍可望保持强势。虽然奥运会这项“重大事件”的积极心理效应在近年来很可能对全国经济发挥了刺激作用，但我们认为奥运结束后，三大区域的投资减速不会呈现很强的同步性。
第三，美国经济周期的反向作用。我们认为，在奥运会开幕前，美国经济周期很可能会呈现弱势，而在奥运结束后，则会趋于回升。这恰恰与奥运会举办国的典型周期走势相反。这种情况有助于熨平2008年上半年和下半年中国的周期性波动。
第四，央行政策立场主导汇率走势。目前，人民银行虽然对美国的衰退前景越发感到担忧，但仍然紧踩刹车。由于通胀率居高不下，人行保持着人民币的快速升值。按年初以来的升值速度推算，人民币对美元全年的涨幅可达16%。人行的政策出发点将是，中国经济能够在全球经济减速的情况下表现出足够的适应能力。不过，一旦中国政府认为，美国经济全面衰退成为最有可能的情况，就会减缓加息和人民币升值的步伐。但迄今为止，鉴于美国经济数据反映的信息还不明朗，即不足以证明衰退的可能性超过了单纯经济减速的可能性，人民币就会继续对美元快速升值。
总之，我们完全承认奥运前后经济走势的历史规律性，即奥运会过后，举办国的经济增长率往往会出现大幅减速；而且我们猜测，中国或许同样会出现这样的趋势。然而，经济规模、经济多样性、美国经济周期走势和央行政策立场等独特因素很可能会抑制中国经济减速的幅度。另一方面，美元－人民币汇率走势仍将更多地决定于中美两国经济周期的总体走势。
北京奥运会确实是影响中国经济前景的因素，但很可能只是次要因素。
英文原文：
Summary and conclusions
This note points out the historical pattern that, since World War II, the economic growth of the host countries of the Summer Olympics usually suffers in the year following the Games. Will China break this 50-year tradition, particular as the weakness in the US economy could be more protracted and the delayed impact of the interest rate hikes and the CNY appreciation should start to act on the economy just as the Olympic torch burns out?
Our focus is on both the capex cycle and the （admittedly unmeasurable, fickle and non-mechanical） sentiment effect of hosting an Olympic Games. While there are a multitude of other factors likely to move the Chinese economy in the next couple of years （including those mentioned above）, we assume them away to bring into sharper relief the one-off effects of hosting such an event, through the capital expenditure cycle.
Historical pattern
We looked at the economic performance of the Olympic host countries （OHCs） since 1956. The striking common feature is an acceleration in GDP growth in the year in which the Olympics were held, followed by a year of sub-par growth. Of the 11 cases we examined since 1956, only the US （Atlanta） in 1996 did not show a slowdown following the Olympics. The slowdown was particularly stark in Australia （1956）, Japan （1964）, the US （1984） and Korea （1988）. Spain actually fell into a recession in 1993. In the two most recent Olympics （Athens and Sydney）, both Greece and Australia decelerated by 1.5-2.0% between the year before and that after the Olympics.
We looked at how the growth, industrial production and national investment growth changed in the 10 quarters before and after the Olympics compared to the average over that period. Average GDP growth deviation from trend tends to decelerate from 1.1% in the year prior to the Olympics to 0.9% in the year of the Olympics, followed by a slowdown to -1.2% in the following year. For investment, the slowdown is even more pronounced: from a 3.3% growth above-trend surge prior to the Olympics to a peak contraction of close to 7% below-trend post-Olympics （for a peak-to-trough swing of 10%）. Also, in terms of timing, it is visually clear that investment has led this up and down cycle around the Olympics. Industrial production exhibits a similar trend. But in terms of severity, it is somewhere between the GDP and the investment trajectories.
The reasons are intuitive
This growth profile should not be too surprising. In the lead-up to the Olympics, it is reasonable to expect large investment, particularly in non-dwelling and hotel construction. Tourism receipts should also surge in the Olympic year. In the case of Beijing, the issue of 'prestige' could also be important, as China tries to showcase its economy and country: doing so costs money and such efforts show up in the GDP. The front-loading of infrastructural and other physical investments naturally implies a slowdown following the Olympics. Just as importantly, a positive sentiment effect may accompany the Olympics, buoying consumption and business investment in areas that are not directly related to the Games or the host city. Such a build-up could be followed by an anticlimactic sentiment effect, as the hype cools down and the world's attention focuses elsewhere.
Currency depreciation following the Olympics
We also examined the performance of the currencies of OHCs. One problem was that, prior to 1971, most of the exchange rates were pegged to the USD and to gold. Pressures on the economy could not be reflected/expressed through exchange rates. We thus focused on experiences after 1972. In Canada （1976）, the US （1984） and Spain （1992）, the currencies of the OHCs depreciated significantly in the two years after the Olympics. In the case of Sydney （2000）, the AUD weakened modestly in the ensuing year. However, in the cases of Seoul （1988） and Athens （2004）, USD/KRW and EUR/USD remained essentially flat over the two-year period, while the USD actually strengthened following the 1996 Atlanta Olympics. Therefore, with a few exceptions, the currency of the host country depreciated when its economic growth decelerated following the Olympics.
The case of China
How will the Summer Olympics affect China's growth rate and the CNY? It would be very difficult to have a precise answer to the above question, mainly because there are direct and indirect effects of the Olympics on economic activities and the value of the CNY. We have the following thoughts:
· Thought 1. China is a big country. The size of the host country is important, as it is essentially only the city that is hosting the Games that should experience large swings in investment and capex cycles. For countries like the US and China, Atlanta or Beijing hosting the Olympics should not have nearly as big an impact on the economy as, say, Seoul, Barcelona and Sydney would have on Korea, Spain and Australia. Thus, we suspect that the contraction in capex following the Beijing Olympics is not likely to be as large as the historical average suggests. The slowdown in US GDP in 1984 （Los Angeles） is miniscule; in 1996 （Atlanta）, US growth actually accelerated, for the simple reason that what happens to a city in a big country shouldn’t dominate the country's GDP.
· Thought 2. China is a diverse country. China is not monolithic, politically, economically or geographically. In a way, China can be broken down into the East （the coastal area）, the Central and the West. The gradation in the levels of economic development and infrastructure build-up is immense across these three broad regions. If the negative demand shock from the US hits the East, the demand for infrastructure and other investment is likely to remain high for the Central and the West. While the positive psychology associated with the 'Big Event' is likely to have been a stimulus for the entire country in recent years, we don't expect the abatement in investment to be very synchronised across the three broad regions right after the Summer Olympics.
· Thought 3. The US business cycle. In our view, the US business cycle will likely show weakness leading to the Olympics, which starts on August 8, 2008, and strength after the Olympics - precisely out of sync with the typical growth cycle surrounding an Olympic Games. This should help to smooth out the growth cycle for China between 1H and 2H.
· Thought 4. The PBoC will, for now, treat the economy as innocent until proven guilty. The PBoC still has its foot on the brake, though it is now more concerned about the prospective recession in the US. For now, the PBoC has continued to let the CNY appreciate rapidly （so far this year, USD/CNY has moved at an annualised pace of 16%）, because inflation remains stubbornly high. The economy will be assumed to show enough resilience against a growth slowdown. But as soon as Beijing comes to the view that an outright US recession is the more probable scenario, it is likely to slow down the pace of interest rate hikes and currency appreciation. But for now, given that the data coming out of the US remain relatively mixed （i.e., not enough to favour a recession over a mere slowdown）, USD/CNY may continue to be guided lower at a rapid pace.
Bottom line
We fully acknowledge the historical regularity with which the growth rate of the country that hosts the Summer Olympics tends to show a pronounced slowdown following the Games, and suspect that we might see this trend in China as well. However, there are special factors that are likely to mute the magnitude of this slowdown. Where USD/CNY goes will still be driven more by the overall path of domestic growth in China and the US business cycle. The Beijing Olympics will likely be a secondary - though legitimate - factor for the growth outlook in China.
