投資界的費曼法則:不要欺騙自己

Forget the 'Dimon principle.' Investors should follow the Feynman principle.

別管什麼“戴蒙法則”(Dimon principle)，投資者應當牢記的是費曼法則(Feynman principle)。

When J.P. Morgan Chase's chief executive, James Dimon, disclosed a $2 billion trading loss during a hastily organized conference call on Thursday, he said: 'This trading may not violate the Volcker rule, but it violates the Dimon principle.'

Associated Press羅伯特•密立根（圖中人物）和理查德•費曼都認爲：對所謂“專家”的結論偏聽偏信是一種自欺行爲。摩根大通(J.P. Morgan Chase)首席執行長傑米•戴蒙(James Dimon)在5月10日召開緊急電話會議，披露該公司發生了20億美元的交易損失。他說，“這筆交易也許沒違反沃爾克法則(Volker Rule)，但違反了戴蒙法則。”

Mr. Dimon didn't say what the Dimon principle is, and a spokesman for the U.S.'s largest bank by assets didn't respond to requests for comment.

戴蒙當時並未對戴蒙法則進行解釋，摩根大通的一位發言人也未對置評請求作出迴應。

The Feynman principle, however, is simple: 'You must not fool yourself-and you are the easiest person to fool,' as the Nobel Prize-winning physicist Richard Feynman put it.

費曼法則卻不難理解，就是諾貝爾獎得主、物理學家理查德•費曼(Richard Feynman)明確指出的，“不要欺騙自己，你自己正是最容易被欺騙的人。”

Asked on April 13 whether J.P. Morgan's trading operation posed significant risks to the bank, Mr. Dimon called it a 'tempest in a teapot.' The bank's chief financial officer insisted the London-based division was merely 'protecting that balance sheet,' adding that J.P. Morgan was 'very comfortable with the positions we have.'

回想4月13日被問及摩根大通交易業務是否對整個銀行構成巨大風險時，戴蒙曾迴應稱這是“小題大做”。摩根大通的首席財務長也堅稱該行位於倫敦的交易部門只是在“保護資產負債表”，並補充稱“摩根大通對當前的頭寸很滿意”。

J.P. Morgan's moguls, in letting a complex risk run wild and denying any potential for error until too late, are a reminder one of the biggest dangers in finance is self-deception.

事到臨頭之前，摩根大通的大佬們這種放任複雜風險失控、矢口否認存在出錯可能性的做法無疑提醒了我們：金融領域最大的危險之一就是自欺欺人。

For investors, the bigger the commitment, the more certain they become that they must have been right to make it-and the harder it becomes to let go.

作爲投資者，對某項投資付出越多，就越相信自己能夠成功，對失敗也就越難以釋懷。

The literal meaning of the word 'invest'-from the Latin vestire, to clothe or dress-is to wrap oneself up in something. Experiments at racetracks and elsewhere have shown that people who bet on an outcome become up to three times more confident that it will occur than people who didn't put up any money.

從字面來看，英語中的“invest”（投資）一詞源自拉丁語中的“vestire”，後者是“穿戴”的意思，即把自己包裹起來。在賽馬場和其它場所進行的實驗表明，相比沒有押注的人，對某一結果押了注的人相信該結果會出現的程度可高出三倍之多。

Not trying to disprove your own beliefs is an especially dangerous deception. In a commencement address he gave to students at the California Institute of Technology in 1974, Mr. Feynman urged his listeners to avoid what he called 'cargo cult' thinking, after Pacific islanders who believed they could make airplanes land, full of food and clothing, by standing alongside makeshift runways, as they had during World War II.

PBS/Everett Collection羅伯特•密立根和理查德•費曼（圖中人物）都認爲：對所謂“專家”的結論偏聽偏信是一種自欺行爲。從不試着反駁自己的信念是一種尤其危險的自欺行爲。1974年費曼在加州理工學院(California Institute of Technology)的畢業典禮致詞上呼籲聽衆避免被他稱爲“草包族”(cargo cult)的思想，就像一些太平洋島民那樣，二次世界大戰結束後他們還以爲守在臨時跑道旁邊就可以等來滿載物資的飛機。

You also can fool yourself by placing too much faith in the findings of supposed experts. Mr. Feynman recounted the story of an influential formula for measuring the charge of an electron that was devised by the pioneering physicist Robert Millikan. The result was slightly wrong, but it took many researchers years to prove it wrong-since Millikan's successors assumed that he had to be right. They adjusted the value, but not enough; deference made them too timid to believe the evidence of their own eyes.

對所謂“專家”的結論偏聽偏信也是一種自欺行爲。費曼講述了先驅物理學家羅伯特•密立根(Robert Millikan)推導出的電子電荷測算公式的故事。其測算結果並不十分準確，但很多研究人員過了多年才得以證明這一點，原因就在於密立根的追隨者們想當然地認爲密立根肯定是正確的。他們調整了數值，但沒有用；對密立根的盲目推崇使他們不敢相信擺在眼前的事實。

Quantitative claptrap can have the same effect on investors. Some banks-including J.P. Morgan-use a technique called 'value at risk,' or VAR, to estimate the potential vulnerabilities of their portfolios. VAR is a short-term measure that generally assumes that past levels of risk and relationships among assets will persist, says Donald van Deventer, author of 'Advanced Financial Risk Management' and chairman of Kamakura Corp., a financial-consulting firm in Honolulu. It gives a precise, but incomplete, picture, he says.

聽起來玄乎其玄的定量術語也會對投資者產生類似的效果。包括摩根大通在內的一些銀行都喜歡採用一種被稱爲“風險價值模型”(VAR)的方法來評估其投資組合的損失風險。火奴魯魯財務諮詢公司Kamakura Corp.董事長、著有《高級金融風險管理》(Advanced Financial Risk Management)一書的唐納德•範•戴維特(Donald van Deventer)指出，風險價值模型是一種短期方法，通常假定過去的風險水平和資產之間的關係不變。他稱，這種方法提供的結果固然精準，卻不全面。

So how can investors avoid deceiving themselves?

那麼，投資者該如何避免自我矇蔽呢？

First of all, remember that 'the riskiest moment is when you are right,' as the economist Peter Bernstein was fond of saying.

首先，記住“最危險的時刻就是你正確的時刻”，這是經濟學家彼得•伯恩斯坦(Peter Bernstein)常說的話。

You should set, in advance, a threshold of profit at which you must review any holding-say, a 50% gain. At that point, you must seek out the opinions of people who think you are wrong-research from short sellers betting against the stock, for example.

你應當提前設定一個盈利底線──例如50%的漲幅，要求自己一旦觸及這個底線就對手中的頭寸進行全面評估。到時候，你必須考慮反方的意見，例如，你持有某隻股票，那就應該仔細研究一下做空這隻股票的人所持的觀點。

Look at the results of other people and organizations that have tried something similar to the actions you are considering. Unless other people have succeeded, there isn't any objective reason to believe that you will. (J.P. Morgan might have notedthe record of big U.S. banks trying to make money off leveraged portfolios of derivatives is abysmal.)

如果你在考慮採取某項行動，還應當先看一下其他已經採取了類似行動的投資者或機構的戰績如何。除非其他投資者取得了成功，否則你也不應當認爲自己就會贏。例如，摩根大通本應該看一下其他美國大銀行在衍生品槓桿投資方面的糟糕記錄。

Monitor yourself for vehemence. If you find yourself tempted to ridicule anyone who tells you are wrong, you probably are wrong. Bertrand Russell warned the less evidence someone has that his ideas are right, 'the more vehemently he asserts that there is no doubt whatsoever that he is exactly right.'

時刻提防自己走向偏激。如果你發現自己開始嘲笑那些說你做錯了的人，那麼你也許真的做錯了。伯特蘭•羅素(Bertrand Russell)曾經警告世人，越是對自己的觀點缺乏證據的人，越是會固執地堅稱自己是絕對正確的。

Finally, try the technique that psychologist Gary Klein calls a 'pre-mortem.' Gather people whose views you respect. Ask them all to imagine looking back, a year from now, at the investment you just made-and that it has turned out to be a disaster. Have them list all the possible causes of the failure. That may well help you see how it might have been avoided.

試試被心理學家加里•克萊因(Gary Klein)稱爲“事前驗屍”(pre-mortem)的方法吧。假設你剛做的投資在一年後慘敗，召集一些你重視其觀點的人，讓他們設想一下從那個時候往回看你所做的投資，並列出他們認爲的可能導致你投資失敗的所有原因。這或許有助於你弄清楚該如何防範於未然。

Above all, remember that the smarter you are, the more easily you can fool yourself.

說到底，就是切記不要“聰明反被聰明誤”。