The parable of the ox – or why it is hard to castrate a bull market

HC案: 這是一則關於股市/牛市的喻言

公牛和市場The parable of the ox – or why it is hard to castrate a bull market作者：英國《金融時報》專欄作家約翰•凱

In 1906, the great statistician Francis Galton observed a competition to guess the weight of an ox at a country fair. Eight hundred people entered. Galton, being the kind of man he was, ran statistical tests on the numbers. He discovered that the average guess (1,197lb) was extremely close to the actual weight (1,198lb) of the ox. This story was told by James Surowiecki, in his entertaining book The Wisdom of Crowds.
1906年，偉大的統計學家弗朗西斯•高爾頓(Francis Galton)在一個鄉下集市上觀察了一場猜測一頭公牛重量的比賽。有八百人參加。出於職業敏感，高爾頓對數據進行了統計檢驗。他發現，猜測的平均值（11971磅）非常接近公牛的實際重量（11981磅）。詹姆斯•蘇洛維爾奇(James Surowiecki)在他有趣的著作《群體智慧》(The Wisdom of Crowds)一書中講述了這個故事。
Not many people know the events that followed. A few years later, the scales seemed to become less and less reliable. Repairs were expensive; but the fair organiser had a brilliant idea. Since attendees were so good at guessing the weight of an ox, it was unnecessary to repair the scales. The organiser would simply ask everyone to guess the weight, and take the average of their estimates.
沒有多少人知道後來發生的故事。幾年後，磅秤似乎變得越來越不可靠。修理磅秤耗資不菲，不過集市組織方想出了一個絕妙的主意。既然參與者如此擅長猜測公牛的體重，那就沒有必要修理磅秤了。組織方只要讓每個人都猜測公牛體重，取他們估計的平均數就可以了。
A new problem emerged, however. Once weight-guessing competitions became the rage, some participants tried to cheat. They even sought privileged information from the farmer who had bred the ox. It was feared that if some people had an edge, others would be reluctant to enter the weight-guessing competition. With only a few entrants, you could not rely on the wisdom of the crowd. The process of weight discovery would be damaged.
不過如此一來又出現了新問題。一旦猜體重比賽風行起來，就會有部分參與者試圖作弊。他們甚至向養牛的農民尋求機密信息。人們擔心，如果有人佔據了優勢，其他人就不願意參與猜體重比賽了。如果只有少數人參與，那就不能依賴群體的智慧了。獲知體重的過程就會受到破壞。
Strict regulatory rules were introduced. The farmer was asked to prepare three monthly bulletins on the development of his ox. These bulletins were posted on the door of the market for everyone to read. If the farmer gave his friends any other information about the beast, that was also to be posted on the market door. Anyone who entered the competition with knowledge concerning the ox that was not available to the world at large would be expelled from the market. In this way, the integrity of the weight-guessing process would be maintained.
由此推出了嚴格的監管規定。農民被要求就他的公牛生長情況準備三份月度公告。這些公告張貼在市場的門口，供所有人閱讀。如果農民向他的朋友透露了任何關於這頭牲畜的信息，這些信息也必須張貼在市場門口。任何參加比賽的人如果知道公眾不了解的公牛信息，就會被驅逐出市場。這樣一來，猜體重過程的公正性得以維護。
Professional analysts scrutinised the contents of these regulatory announcements and advised their clients on their implications. They wined and dined farmers; once the farmers were required to be careful about the information they disclosed, however, these lunches became less fruitful.
專業分析人士仔細審查這些監管公告的內容，就其意義向他們的顧客提供諮詢。這些專業人士請農民喝酒吃飯。但一旦農民被要求謹慎對待他們披露的信息，飯局的成果就不是那麼豐碩了。
Some brighter analysts realised that understanding the nutrition and health of the ox was not that useful anyway. What mattered were the guesses of the bystanders. Since the beast was no longer being weighed, the key to success lay not in correctly assessing its weight, but rather in correctly assessing what other people would guess. Or what others would guess others would guess. And so on.
一些更聰明的分析人士認識到，了解公牛的營養和健康狀況不再有用。重要的是旁觀者如何猜測。由於組織方不再稱公牛的體重，所以成功的關鍵不在於正確估計公牛的體重，而是正確地估計其他人如何猜測。或者說，其他人如何猜測其他人怎麼猜測。如此擴展下去。
Some, such as old Farmer Buffett, claimed that the results of this process were more and more divorced from the realities of ox-rearing. He was ignored, however. True, Farmer Buffett's beasts did appear healthy and well fed, and his finances were ever more prosperous: but, it was agreed, he was a simple countryman who did not really understand how markets work.
有些人，例如老農民巴菲特(Buffett)聲稱，這一過程的結果日益偏離養牛的現實。但沒有人理會他。確實，農民巴菲特的牲畜看上去很健康，餵養得當，收入前景也越來越好。但大家公認他只是一名頭腦簡單的鄉下人，不明白市場的運作機制。
International bodies were established to define the rules for assessing the weight of the ox.
於是國際組織得以設立，規定了評估公牛體重的規則。
There were two competing standards – generally accepted ox-weighing principles and international ox-weighing standards. However, both agreed on one fundamental principle, which followed from the need to eliminate the role of subjective assessment by any individual. The weight of the ox was officially defined as the average of everyone's guesses.
存在兩種相互競爭的標準：普遍接受的公​​牛體重評估原則和國際公牛體重評估標準。不過，兩項標準都認同一項基本原則，即有必要消除任何個人進行的主觀評估。公牛的體重被正式規定為所有人猜測的平均值。
One difficulty was that sometimes there were few, or even no, guesses of the oxen's weight. But that problem was soon overcome. Mathematicians from the University of Chicago developed models from which it was possible to estimate what, if there had actually been many guesses as to the weight of the animal, the average of these guesses would have been. No knowledge of animal husbandry was required, only a powerful computer.
有一個難題是，有時只有很少的人、或者根本沒有人來猜公牛的體重。不過這個問題很快就被攻克了。芝加哥大學(University of Chicago)的數學家開發了模型。這個模型可以估計出，假如對公牛的體重真的有過很多猜測，這些猜測的平均值會是多少。如此一來，完全不需要了解牲畜飼養的知識，只要有台強大的電腦即可。
By this time, there was a large industry of professional weight guessers, organisers of weight-guessing competitions and advisers helping people to refine their guesses. Some people suggested that it might be cheaper to repair the scales, but they were derided: why go back to relying on the judgment of a single auctioneer when you could benefit from the aggregated wisdom of so many clever people?
此時已湧現出一個龐大的行業，其中包括專業的體重猜測師、猜體重比賽組織者、以及幫助人們完善猜測的顧問。有人建議，修理磅秤的成本可能更低，但這些人遭到奚落：既然能夠從如此多聰明人的群體智慧中受益，又何必回到只依賴一名拍賣人的判斷的日子呢？
And then the ox died. Among all this activity, no one had remembered to feed it.
接下來，公牛死了。在這些紛紛擾擾的活動中，沒有人記得去餵牠。

譯者/倪衛國