Dan Arielyの静かなプレゼン
I'll tell you a little bit about irrational behavior. Not yours, of course -- other people's.(Laughter)
So after being at MIT for a few years, I realized that writing academic papers is not that exciting. You know, I don't know how many of those you read, but it's not fun to read and often not fun to write -- even worse to write（書く方がもっと退屈です）. So I decided to try and write something more fun. And I came up with an idea that I will write a cookbook. And the title for my cookbook was going to be "Dining Without Crumbs: The Art of Eating Over the Sink.（パン屑なしの食事：シンクの上で食べる技術）" (Laughter) And it was going to be a look at life through the kitchen. And I was quite excited about this. I was going to talk a little bit about research, a little bit about the kitchen. You know, we do so much in the kitchen I thought this would be interesting. And I wrote a couple of chapters.And I took it to MIT press and they said, "Cute, but not for us. Go and find somebody else." I tried other people and everybody said the same thing, "Cute. Not for us."
Until somebody said, "Look, if you're serious about this, you first have to write a book about your research. You have to publish something, and then you'll get the opportunity to write something else. If you really want to do it you have to do it." So I said, "You know, I really don't want to write about my research. I do this all day long. I want to write something else.Something a bit more free, less constrained." And this person was very forceful and said,"Look. That's the only way you'll ever do it.（それをやるにはこの方法しかありませんよ）" So I said, "Okay, if I have to do it --（分かったよ、仕方ないな） " I had a sabbatical（研究休暇：sabbatical year 大学教授に与えられる1年または半年の有給休暇。元々の意味は安息日）. I said, "I'll write about my research if there is no other way. And then I'll get to do my cookbook." So I wrote a book on my research.
And it turned out to be quite fun in two ways. First of all, I enjoyed writing. But the more interesting thing was that I started learning from people. It's a fantastic time to write,because there is so much feedback you can get from people. People write me about their personal experience, and about their examples, and what they disagree, and nuances. And even being here -- I mean the last few days, I've known really heights of obsessive（偏執的に頭から離れない） behavior I never thought about. (Laughter) Which I think is just fascinating.
I will tell you a little bit about irrational behavior. And I want to start by giving you some examples of visual illusion as a metaphor for rationality（合理性）. So think about these two tables.And you must have seen this illusion. If I asked you what's longer, the vertical line on the table on the left, or the horizontal line on the table on the right? Which one seems longer?Can anybody see anything but the left one being longer? No, right? It's impossible. But the nice thing about visual illusion is we can easily demonstrate mistakes. So I can put some lines on; it doesn't help. I can animate the lines. And to the extent you believe I didn't shrink the lines, which I didn't, I've proven to you that your eyes were deceiving you（あなたの目があなたをだましているのです）. Now, the interesting thing about this is when I take the lines away, it's as if you haven't learned anything in the last minute. (Laughter) You can't look at this and say, "Okay now I see reality as it is." Right? It's impossible to overcome this sense that this is indeed longer. Our intuition is really fooling us in a repeatable, predictable, consistent way. And there is almost nothing we can do about it, aside from taking a ruler（定規） and starting to measure it.
Here is another one -- this is one of my favorite illusions. What do you see the color that top arrow is pointing to? Brown. Thank you. The bottom one? Yellow. Turns out they're identical（turn outで結局〜になる、identicalは同一である、＝実はそれらは同じなのです）. Can anybody see them as identical? Very very hard. I can cover the rest of the cube up. And if I cover the rest of the cube you can see that they are identical. And if you don't believe me you can get the slide later and do some arts and crafts and see that they're identical. But again it's the same story that if we take the background away, the illusion comes back. Right. There is no way for us not to see this illusion. I guess maybe if you're colorblind I don't think you can see that. I want you to think about illusion as a metaphor.
Vision is one of the best things we do. We have a huge part of our brain dedicated to vision -- bigger than dedicated to anything else. We do more vision more hours of the day than we do anything else. And we are evolutionarily designed to do vision. And if we have these predictable repeatable mistakes in vision, which we're so good at（もしも私たちが視界、私たちが得意とするものの中で、予測できる上に繰り返してしまうミスを持っているとするならば）, what's the chance that we don't make even more mistakes in something we're not as good at -- for example, financial decision making（私たちが得意としない分野において、私たちがミスを犯す確率はなんぼのもんでしょうか？例えば、投資判断。）: (Laughter) something we don't have an evolutionary reason to do,we don't have a specialized part of the brain, and we don't do that many hours of the day.And the argument is in those cases it might be the issue that we actually make many more mistakes and, worse, not have an easy way to see them（論点は、これらのケースにおいての、私たちは実際により多くのミスを犯しているということと、もっと悪いことに、それらに気付く簡単な方法を持たないということです）. Because in visual illusions we can easily demonstrate the mistakes; in cognitive illusion it's much, much harder to demonstrate to people the mistakes.
So I want to show you some cognitive illusions, or decision-making illusions, in the same way. And this is one of my favorite plots in social sciences. It's from a paper by Johnson and Goldstein. And it basically shows the percentage of people who indicated they would be interested in giving their organs to donation. And these are different countries in Europe. And you basically see two types of countries: countries on the right, that seem to be giving a lot; and countries on the left that seem to giving very little, or much less. The question is, why? Why do some countries give a lot and some countries give a little?
When you ask people this question, they usually think that it has to be something about culture. Right? How much do you care about people? Giving your organs to somebody else is probably about how much you care about society, how linked you are. Or maybe it is about religion. But, if you look at this plot, you can see that countries that we think about as very similar actually exhibit very different behavior. For example, Sweden is all the way on the right, and Denmark, that we think is culturally very similar, is all the way on the left.Germany is on the left. And Austria is on the right. The Netherlands is on the left. And Belgium is on the right. And finally, depending on your particular version of European similarity, you can think about the U.K and France as either similar culturally or not. But it turns out that from organ donation they are very different.
By the way, the Netherlands is an interesting story. You see the Netherlands is kind of the biggest of the small group(オランダは関心が小さいグループの中では、最も大きいです). Turns out that they got to 28 percent after mailing every household in the country a letter begging（懇願する） people to join this organ donation program. You know the expression, "Begging only gets you so far（頼まれてするにも限度がある）"? It's 28 percent in organ donation.
(Laughter)
But whatever the countries on the right are doing they are doing a much better job than begging. So what are they doing? Turns out the secret has to do with a form at the DMV（運輸局）.And here is the story. The countries on the left have a form at the DMV that looks something like this. Check the box below if you want to participate in the organ donor program. And what happens? People don't check, and they don't join. The countries on the right, the ones that give a lot, have a slightly different form. It says check the box below if you don't want to participate. Interestingly enough, when people get this, they again don't check -- but now they join.
(Laughter)
Now think about what this means. We wake up in the morning and we feel we make decisions. We wake up in the morning and we open the closet and we feel that we decide what to wear. And we open the refrigerator and we feel that we decide what to eat. What this is actually saying is that much of these decisions are not residing（reside：備わっている） within us. They are residing in the person who is designing that form（その意思決定は、その記入用紙をデザインした人に帰属しているのです）. When you walk into the DMV, the person who designed the form will have a huge influence on what you'll end up doing. Now it's also very hard to intuit（直観する） these results. Think about it for yourself. How many of you believe that if you went to renew your license tomorrow, and you went to the DMV, and you would encounter one of these forms, that it would actually change your own behavior? Very, very hard to think that you will influence us. We can say, "Oh, these funny Europeans, of course it would influence them." But when it comes to us, we have such a feeling that we are at the driver's seat, we have such a feeling that we are in control, and we are making the decision, that it's very hard to even accept the idea that we actually have an illusion of making a decision, rather than an actual decision.
Now, you might say, "These are decisions we don't care about." In fact, by definition, these are decisions about something that will happen to us after we die. How could we care about something less than something that happens after we die? So a standard economist, someone who believes in rationality, would say, "You know what? The cost of lifting the pencil and marking a V is higher than the possible benefit of the decision, so that's why we get this effect." But, in fact, it's not because it's easy. It's not because it's trivial（取るに足らない）. It's not because we don't care. It's the opposite. It's because we care. It's difficult and it's complex.And it's so complex that we don't know what to do. And because we have no idea what to do we just pick whatever it was that was chosen for us.
I'll give you one more example for this. This is from a paper by Redelmeier and Schaefer.And they said, "Well, this effect also happens to experts, people who are well-paid, experts in their decisions, do it a lot." And they basically took a group of physicians. And they presented to them a case study of a patient. Here is a patient. He is a 67-year-old farmer.He's been suffering from a right hip pain for a while. And then they said to the physician,"You decided a few weeks ago that nothing is working for this patient. All these medications, nothing seems to be working. So you refer the patient to hip replacement therapy. Hip replacement. Okay?" So the patient is on a path to have his hip replaced. And then they said to half the physicians, they said, "Yesterday you reviewed the patient's case and you realized that you forgot to try one medication. You did not try ibuprofen. What do you do? Do you pull the patient back and try ibuprofen? Or do you let them go and have hip replacement?" Well the good news is that most physicians in this case decided to pull the patient and try the ibuprofen. Very good for the physicians.
The other group of the physicians, they said, "Yesterday when you reviewed the case you discovered there were two medications you didn't try out yet, ibuprofen and piroxicam." And they said, "You have two medications you didn't try out yet. What do you do? You let them go. Or you pull them back. And if you pull them back do you try ibuprofen or piroxicam? Which one?" Now think of it. This decision makes it as easy to let the patient continue with hip replacement. But pulling them back, all of the sudden becomes more complex. There is one more decision. What happens now? Majority of the physicians now choose to let the patient go to hip replacement. I hope this worries you, by the way -- (Laughter) when you go to see your physician. The thing is is that no physician would ever say, "Piroxicam, ibuprofen, hip replacement. Let's go for hip replacement." But the moment you set this as the default it has a huge power over whatever people end up doing.
I'll give you a couple of more examples on irrational decision-making. Imagine I give you a choice. Do you want to go for a weekend to Rome? All expenses paid: hotel, transportation, food, breakfast, a continental breakfast, everything. Or a weekend in Paris? Now, a weekend in Paris, a weekend in Rome, these are different things; they have different food, different culture, different art. Now imagine I added a choice to the set that nobody wanted.Imagine I said, "A weekend in Rome, a weekend in Paris, or having your car stolen?"(Laughter) It's a funny idea, because why would having your car stolen, in this set, influence anything? (Laughter) But what if the option to have your car stolen was not exactly like this. What if it was a trip to Rome, all expenses paid, transportation, breakfast,but doesn't include coffee in the morning. If you want coffee you have to pay for it yourself. It's two euros 50. Now in some ways, given that you can have Rome with coffee, why would you possibly want Rome without coffee? It's like having your car stolen. It's an inferior option. But guess what happened. The moment you add Rome without coffee,Rome with coffee becomes more popular. And people choose it. The fact that you have Rome without coffee makes Rome with coffee look superior, and not just to Rome without coffee -- even superior to Paris. (Laughter)
Here are two examples of this principle. This was an ad from The Economist a few years ago that gave us three choices. An online subscription for 59 dollars. A print subscription for 125. Or you could get both for 125. (Laughter) Now I looked at this and I called up The Economist. And I tried to figure out what were they thinking. And they passed me from one person to another to another, until eventually I got to a person who was in charge of the website. And I called them up. And they went to check what was going on. The next thing I know, the ad is gone. And no explanation.
So I decided to do the experiment that I would have loved The Economist to do with me. I took this and I gave it to 100 MIT students. I said, "What would you choose?" These are the market share. Most people wanted the combo deal. Thankfully nobody wanted the dominated option. That means our students can read. (Laughter) But now if you have an option that nobody wants, you can take it off. Right? So I printed another version of this,where I eliminated the middle option. I gave it to another 100 students. Here is what happens. Now the most popular option became the least popular. And the least popular became the most popular.
What was happening was the option that was useless, in the middle, was useless in the sense that nobody wanted it. But it wasn't useless in the sense that it helped people figure out what they wanted. In fact, relative to the option in the middle, which was get only the print for 125, the print and web for 125 looked like a fantastic deal. And as a consequence, people chose it. The general idea here, by the way, is that we actually don't know our preferences that well. And because we don't know our preferences that well we're susceptible（影響を受けやすい） to all of these influences from the external forces: the defaults, the particular options that are presented to us, and so on（私たちは自分の好みを知らないが故に、外部の力からくる影響にとても影響を受けやすいのです、例えば、デフォルトの設定や、特別なオプションなどです）.
One more example of this. People believe that when we deal with physical attraction, we see somebody, and we know immediately whether we like them or not, attracted or not.Which is why we have these four-minute dates. So I decided to do this experiment with people. I'll show you graphic images of people -- not real people. The experiment was with people. I showed some people a picture of Tom, and a picture of Jerry. I said "Who do you want to date? Tom or Jerry?" But for half the people I added an ugly version of Jerry. I took Photoshop and I made Jerry slightly less attractive. (Laughter) The other people, I added an ugly version of Tom. And the question was, will ugly Jerry and ugly Tom help their respective, more attractive brothers? The answer was absolutely yes. When ugly Jerry was around, Jerry was popular. When ugly Tom was around, Tom was popular.
(Laughter)
This of course has two very clear implications for life in general. If you ever go bar hopping, who do you want to take with you? (Laughter) You want a slightly uglier version of yourself.(Laughter) Similar. Similar ... but slightly uglier. (Laughter) The second point, or course, is that if somebody else invites you, you know how they think about you. (Laughter) Now you're getting it.
What is the general point? The general point is that when we think about economics we have this beautiful view of human nature. "What a piece of work is man! How noble in reason!" We have this view of ourselves, of others. The behavioral economics perspective is slightly less generous to people. In fact in medical terms, that's our view. (Laughter) But there is a silver lining(光明、明るい兆し). The silver lining is, I think, kind of the reason that behavioral economics is interesting and exciting. Are we Superman? Or are we Homer Simpson?
When it comes to building the physical world, we kind of understand our limitations. We build steps. And we build these things that not everybody can use obviously. (Laughter) We understand our limitations, and we build around it. But for some reason when it comes to the mental world, when we design things like healthcare and retirement and stockmarkets,we somehow forget the idea that we are limited. I think that if we understood our cognitive limitations in the same way that we understand our physical limitations, even though they don't stare（目立つ） us in the face in the same way, we could design a better world. And that, I think, is the hope of this thing.
Thank you very much.
(Applause)
話の要点としては、
- 人は自分の行動を自分自身の純粋な意志によって選択している（意思決定している）と思い込んでいるが、実は与えられる選択肢の「見え方」によって影響を受けている。
- 直感的にそれを理解するいい方法が、錯視。図形があなたをだますのではなく、「あなたの目」があなたの認識をだます。そして、（二つのテーブルの長辺を比べる例がいい例だが）一度その間違いを指摘されたとしても、錯視は何度でも繰り返しおきる。そのように脳が認識してしまうことを止められない。（定規を使って実測するまでは）
- 錯視の例は、実は最も単純で、その間違いに気付きやすい。視覚は人間の感覚の中でもっとも優れているからだ。むしろ問題は、視覚ではなく、認識や抽象的概念における錯視的問題。いい例が、株式投資、年金システム、健康保険。認識や抽象的思考は、人間が本来得意とするものではなく、それ故に、錯視的ミス（ミスに気付くことすら難しい）が起きやすい。
- 取るに足らないことだから適当に選んで錯視的ミスを犯す、のではない。むしろ逆で、よく分からない複雑なことだからこそ、既に用意されている選択肢を安易に選んでしまう。
- 錯視的ミスの例：旅費、食費全てをこちらもちにするから、ローマとパリどちらに行きたい？という選択では、大体イーブン。しかし、選択肢を、「全額を出すローマ」、「朝のコーヒー以外全額を出すローマ」、「全額をだすパリ」とすると、「全額を出すローマ」が最も人気になる。パリも抜いて。同様に、「59ドルでNewsweekのWeb版定期購読」と「125ドルでNewsweek雑誌版とWeb版の定期購読」の二つの選択では、59ドルのWeb版のみが一番人気となるが、この二つの選択肢に「125ドルでNewsweek雑誌のみ定期購読」という魅力のない選択肢を加えると、認識に錯覚が起こる。つまり、「125ドルでNewsweek雑誌版とWeb版の定期購読」の選択肢があたかも「125ドルで雑誌もWebも両方も手に入る！お買い得！」というように見えて、125ドルの両方版が一番人気になる。
- このように、人は自分の趣味や趣向を知っているようで知らない。
- 「似ているけれど魅力的ではない選択肢」を用意することで、「似ている平凡な選択肢」を選ばせることができる。例えば合コンにどのような友達を連れて行くべきか？それは「自分と似ているけれど、ちょっと醜い友達」だ（悪いジョークだが、行動経済学的には最良の選択）。
人はより楽な選択肢を選びたがるし、それが複雑な（すぐに分からないような）内容である程、顕著に現れやすい。
この話を聞いて思ったのは、携帯電話のプラン説明。「なんだかよく分からないけど、一番おすすめのやつで。」とやってしまいがちだ。説明のパンフレットもそうなるように仕向けられているように思える。
