But there are more modest ways his insights can help us avoid making mistakes. He advises, for example, that meetings start with participants writing down their ideas about the issue at hand before anyone speaks. That way, the halo effect – whereby the concerns raised first and most assertively dominate the discussion – can be mitigated, and a range of views considered. Then there is the concept of adversarial collaboration, an attempt to do away with pointless academic feuding. Though he doesn’t like to think in terms of leaving a legacy, it’s one thing he says he hopes to be remembered for. In the early 2000s Kahneman sought out a leading opponent of his view that so-called expert judgments were frequently flawed. Gary Klein’s research focused on the ability of professionals such as firefighters to make intuitive but highly skilled judgments in difficult circumstances. “We spent five or six years trying to figure out the boundary, where he’s right, where I am right. And that was a very satisfying experience. We wrote a paper entitled ‘A Failure to Disagree’”.






昨日エントリで紹介したガーディアン記事は、「Daniel Kahneman: ‘What would I eliminate if I had a magic wand? Overconfidence’」と題されていた。以下は、そのタイトルの元となった箇所の引用(Mostly Economicsが引用した箇所でもある)。

What’s fascinating is that Kahneman’s work explicitly swims against the current of human thought. Not even he believes that the various flaws that bedevil decision-making can be successfully corrected. The most damaging of these is overconfidence: the kind of optimism that leads governments to believe that wars are quickly winnable and capital projects will come in on budget despite statistics predicting exactly the opposite. It is the bias he says he would most like to eliminate if he had a magic wand. But it “is built so deeply into the structure of the mind that you couldn’t change it without changing many other things”.

The same applies to our habit of predicting stereotypical outcomes at the expense of what’s known about the world. When told of a student, Tom, who has a preference for neat and tidy systems and a penchant for sci-fi, most of us guess that he’s studying computer sciences and not a humanities subject. This is despite the fact that the group studying the latter is far larger. “Think of it this way. A form of stereotyping is involved in understanding the world. So I have a stereotype of a table, I have a stereotype of chairs. Now when you start having stereotypes of social groups, it’s the human mind at work. It’s not a different mind. It’s what you need to get around in the world.” You can slow down and become aware of this, Kahneman believes, but the underlying mechanism isn’t going to change.



同じことは、世界について知られていることを無視してステレオタイプな結果を予測する我々の習慣にも当てはまる。きちんと整備された体系を好み、SFを趣味とする学生トムのことを聞いたならば、我々の多くは、彼が文系ではなくコンピュータ科学を専攻していると推測する。文系を専攻している学生が圧倒的に多いにも関わらず、である。「このように考えてみてほしい。ステレオタイプに落とし込むやり方というのは世界を理解することに伴うものだ。従って私は椅子に関するステレオタイプを持っているし、机に関するステレオタイプを持っている。社会的集団についてステレオタイプを持つようになったということは、そうした人間の心理が作用しているということだ。違う心理が作用しているわけではない。それは世界で生きていくために必要な心理作用なのだ。」 少しペースダウンしてこのことを意識することはできるが、裏にあるメカニズムが変わることは無い、とカーネマンは考えている。




先月半ばのガーディアンダニエル・カーネマンのインタビュー記事が掲載されている(H/T Mostly Economics)。そこではナチスの迫害から逃げ回った少年時代が語られた後に、イスラエルでのパレスチナ問題に関する彼の見方が示されている。

As an Israeli, there at the very birth of the nation, Kahneman has had a front-row seat in one of the most vivid theatres of human misunderstanding. His work has much to say about prejudice, the inability to fully recognise alternative points of view and our strong aversion to losses, which considerably outweighs the satisfaction we get from gains. Can he explain why, in this area, it’s been so hard to achieve a meeting of minds?

“I’m far on the left of the spectrum in Israeli politics and always have been,” he says. “I hated the notion of occupation since the very beginning. My first memories from after the 67 war are travelling with my children in the occupied territories. There were awnings over groceries stores with Hebrew lettering advertising Osem noodles. I couldn’t bear it. I thought that was dreadful because I remembered German lettering in France. I have very strong feelings about Israel as an occupier.”

Despite this, Kahneman has found it impossible to envisage a settlement that will satisfy both sides. “I don’t believe in the power of rational argument in this context,” he says, with an air of resignation. He mentions one occasion when he was visited at his university by a Palestinian academic after 67. They were getting on famously. But then “we tried to negotiate peace, and we failed, essentially on the right of return, which although obviously a legitimate demand among the Palestinians, means the destruction of Israel. So people who don’t want Israel destroyed cannot accept the right of return, even though they might understand that it has legitimacy behind it.”








ライト兄弟が飛行機を発明したにも関わらず、なぜその後に米国航空機業界で優位に立てなかったのか、という点について、Tim Taylorが以下の論文から引用を行っている

Blaming Wilbur and Orville

The answer lies in a 1913 congressional study of aeronautical expenditures by the nations of the world. Germany led the world, with $28,000,000 spent on aviation between 1908 and 1913. France, Russia, Italy, and Austria followed close behind, with England in sixth place with a total national expenditure of $3,000,000 for aeronautics. Having spent only $435,000 for all flight-related activity during that five-year period, the United States was in thirteenth place, behind Japan, Chile, Greece, and Brazil. (All figures are from Aeronautics in the Army, hearing before the Committee on Military Affairs, U.S. House of Representatives, sixty-third Congress, first session, 1913.) In addition to official appropriations, several leading aeronautical powers had also established national subscriptions that provided an additional $7,100,000 in private financial support for their aeronautical industries. Once again, Germany led the way, with $3,500,000 in private funds, followed by France ($2,500,000), Italy ($1,000,000), and Russia ($100,000). According to official U.S. government estimates, the other nations of the world had spent a total of $93,620,000 in public and private funds on aviation between 1908 and 1913.




That America had fallen far behind Europe in aviation by 1917 is beyond doubt. Every American airman who flew into combat in the “war to end all wars” did so in an airplane entirely designed and almost entirely built in Europe, except for those naval aviators operating Curtiss flying boats in search of enemy U-boats.



一般には、ライト兄弟の会社(Wright Company)と、カーチス社など他の航空機製造会社との特許紛争が米国航空機業界の足を引っ張ったとされるが(ちなみに後の1929年にライト社とカーチス社は結局合併することになる)、Crouch論文ではその見方は否定され、つまるところは軍事的必要性とカネが物を言ったのだ、という見解を示している。

In America, ... flying was the domain of aerial showmen out to thrill the crowds at local meets and air shows with old-style pusher biplanes. In Europe, on the other hand, rich prizes were established to promote improvements in airframe and engine technology. Competition encouraged the development of aircraft that could fly higher, faster, and farther. ... With war clouds glowering on the horizon, European nations had invested heavily in a set of new technologies with military potential. Americans, an ocean away from potential conflict, did not see the need to support the embryonic industry. ... [T]he failure of other American aircraft builders to keep up with advances in Europe had little to do with the patent wars and everything to do with a limited market and the low level of public and private investment in flight technology.






「紐を押す」という言葉の起源はしばしばケインズに帰せられるが*1Tim Taylorがそれについて以下のように書いている

Although I have seen the "can't push on a string" metaphor attributed to John Maynard Keynes in a number of places, I haven't seen an actual primary source where Keynes used the phrase.




Governor Eccles: Under present circumstances there is very little, if anything, that can be done.

Mr. Goldsborough: You mean you cannot push a string.

Governor Eccles: That is a good way to put it, one cannot push a string. We are in the depths of a depression and, as I have said several times before this committee, beyond creating an easy money situation through reduction of discount rates and through the creation of excess reserves, there is very little, if anything that the reserve organization can do toward bringing about recovery. I believe that in a condition of great business activity that is developing to a point of credit inflation monetary action can very effectively curb undue expansion.

Mr. Brown: That is a case of pulling the string.

Governor Eccles: Yes. Through reduction of discount rates, making cheap money and creating excess reserves, there is also a possibility of stopping deflation, particularly if that power is used combined with this broadening of eligibility requirement.




Later in the hearings, several other speakers refer back to the "push on a string" comment, which clearly had some resonance.




*2:ゴールズボローのWikipediaエントリや「Pushing on a string」のWikipediaエントリにもその旨の記述がある。

*3:Taylorがリンクしたこちらのサイトによると、「Marriner S. Eccles was appointed chairman (called “governor” before 1935) of the Federal Reserve Board on November 15, 1934.」との由。エクルズについてはこちらのエントリも参照。

*4Prentiss M. Brown民主党ミシガン)。