How does Great Britain's haul of 64 medals, including 29 golds, compare to other recent host nations' performance?
英国在本届奥运会上获得64枚奖牌，包括29枚金牌，这样的表现与前几届奥运会的主办国如何对比？
There can be little doubt that greater recent investment in elite sports is the main cause of Great Britain's impressive performance at these Olympics an uptick in performance compared with Beijing 2008 would have been expected regardless, because of a well-documented "host-nation effect" that sees the home team performed significantly better than it usually does.
无疑，近年对精英运动项目加大投资，是英国在本届奥运会上取得骄人战绩的主要原因。但是，英国军团的表现会比2008年北京奥运会时好一些，本来就在意料之中，这是由于已有大量研究文献支持的"主办国效应"，即奥运主办国代表队的表现会显著好于其正常水平。
One of the economists who have studied the factors that effect nations' Olympic performance, Daniel Johnson of Colorado College, found that the benefits of hosting are not one-offs. His work describes both a "pre-hosting effect" that benefits the host nation of the next Olympics, and a "legacy" or "post-hosting effect" that sees the hosts of the last two Olympics continue to outperform expectations.
对于影响一国奥运表现的各种因素，科罗拉多学院(Colorado College)的丹尼尔•约翰逊(Daniel Johnson)是进行了相关研究的经济学家之一。他发现，主办奥运会的效益并不是一次性的。他在研究后总结出两种效应：一是造福于下一届奥运会主办国的"主办前效应"，二是有利于上两届奥运会主办国继续超常发挥的一种"遗赠"或曰"主办后效应"。
Johnson's obervation can be seen clearly in the chart above: Host nations' performance begins to improve before their home Olympics, and only gradually reverts afterwards.
约翰逊的观察从以上图表可明显看出：主办国的表现在其主办奥运会之前就开始提高，而在主办之后却不是一下子就回归常态。
In 2000, economists Andrew Bernard and Meghan Busse analysed the historical medal tables and found that host nations won 1.8 per cent more medals than could be predicted from GDP alone. Their work was updated for the current games by London Business School PhD student Emily Williams, who predicted that Team GB would win 62 medals including 25 golds.
2000年，经济学家安德鲁•伯纳德(Andrew Bernard)和梅根•布斯(Meghan Busse)分析了历届奥运会的奖牌榜。他们发现，与仅仅依据国内生产总值(GDP)作出的预测相比，主办国能够多赢得1.8%的奖牌。伦敦商学院(LBS)的博士生艾米莉•威廉姆斯(Emily Williams)联系本届奥运会的实际，对他们的研究进行了修正，她预测英国军团会获得62枚奖牌，包括25枚金牌。
A similar analysis published in a Goldman Sachs report earlier this summer found that host nations usually enjoy a 54% increase in medals, and showed that certain sports are more sensitive to the host-nation effect than others. The bank was more bullish on Great Britain's chances, offering a near-perfect prediction of 64 medals and 30 golds.
今年夏初时分，高盛(Goldman Sachs)的一份报告发表了一项类似的分析。该项研究发现，主办国通常能够多获得54%的奖牌，而且某些比赛项目对主办国效应更为敏感。该行当时对英国军团的前景更为乐观，作出了近乎完美的预测：64枚奖牌，包括30枚金牌。
Our chart excludes the boycott games of Moscow 1980 and Los Angeles 1984 which had exaggerated host-nation effects, along with the 1972 and 1976 games, whose hosts West Germany and Canada would go on to be major beneficiaries of the Soviet-bloc boycott of the Los Angeles games in 1984. It also excludes the Atlanta games of 1996, because the United States data for this line would include the problematic 1984 games.
我们的图表剔除了1980年莫斯科奥运会和1984年洛杉矶奥运会（因为这两届奥运会都遭到抵制，夸大了主办国效应），也剔除了1972年慕尼黑奥运会和1976年蒙特利尔奥运会（因为主办国西德和加拿大后来在1984年洛杉矶奥运会上都明显获益于苏联集团国家的抵制）。图表还剔除了1996年亚特兰大奥运会（因为这条线上的美国数据将包括有问题的1984年奥运会）。