誘惑される意志

by ジョージ・エインズリー

というのがあるらしい。パーフィットと関係しそう。

自己成就的な機能を持った予測

予測から予定への関数の不動点としての意思

信念は欲求を充足するための行動だけれど、その欲求とは「もしpであるならば、『p』と信じたい。もし¬pであるならば、『¬p』と信じたい」という形をした欲求なのかもしれないよ?

?? なんで論理実証主義が唯名論じゃなくて実念論ってことになってるんだ ??

(そもそも普遍論争を擬似問題と扱ったかもしれない)

一貫していないとか他人に搾取されない選好を持つのはよくないというのはどこから正当化できるか。

本人が一貫しない選好を持ちたくないというメタ選好を持っている?

いや、双曲的な時間割引がよくないという理由に、ダッチブック論証みたいのを持ち出す必要は別に無いのでは。

単に、他人が時点間で再分配することでどの時点のその人にとっても悪くなく、少なくとも1つの時点のその人については双曲的より良い結果になることをしめせばいい

つまり、その人が時点時点の効用をパレート効率的に最大化していないことを示せばいいのだ

あるいは、(似たことだけど)時点間の自己が社会契約を行ったら、双曲的な状態を好むかを考えてみてもいい

指数的時間選好は不平等だけど効率的な世界、双曲的時間選好は効率的でないせかい

そもそも時間選好を持たないのは平等

すべり坂論法

But suppose we offered Gandhi $1 million to take a different pill: one which would decrease his reluctance to murder by 1%. This sounds like a pretty good deal. Even a person with 1% less reluctance to murder than Gandhi is still pretty pacifist and not likely to go killing anybody. And he could donate the money to his favorite charity and perhaps save some lives. Gandhi accepts the offer.

Now we iterate the process: every time Gandhi takes the 1%-more-likely-to-murder-pill, we offer him another $1 million to take the same pill again.

Maybe original Gandhi, upon sober contemplation, would decide to accept $5 million to become 5% less reluctant to murder. Maybe 95% of his original pacifism is the only level at which he can be absolutely sure that he will still pursue his pacifist ideals.

Unfortunately, original Gandhi isn't the one making the choice of whether or not to take the 6th pill. 95%-Gandhi is. And 95% Gandhi doesn't care quite as much about pacifism as original Gandhi did. He still doesn't want to become a murderer, but it wouldn't be a disaster if he were just 90% as reluctant as original Gandhi, that stuck-up goody-goody.

What if there were a general principle that each Gandhi was comfortable with Gandhis 5% more murderous than himself, but no more? Original Gandhi would start taking the pills, hoping to get down to 95%, but 95%-Gandhi would start taking five more, hoping to get down to 90%, and so on until he's rampaging through the streets of Delhi, killing everything in sight.

Now we're tempted to say Gandhi shouldn't even take the first pill. But this also seems odd. Are we really saying Gandhi shouldn't take what's basically a free million dollars to turn himself into 99%-Gandhi, who might well be nearly indistinguishable in his actions from the original?

Maybe Gandhi's best option is to "fence off" an area of the slippery slope by establishing a Schelling point - an arbitrary point that takes on special value as a dividing line. If he can hold himself to the precommitment, he can maximize his winnings. For example, original Gandhi could swear a mighty oath to take only five pills - or if he didn't trust even his own legendary virtue, he could give all his most valuable possessions to a friend and tell the friend to destroy them if he took more than five pills. This would commit his future self to stick to the 95% boundary (even though that future self is itching to try to the same precommitment strategy to stick to its own 90% boundary).

ピコ経済学

In Human Action (chapter 18), Ludwig von Mises discusses time inconsistency: that sooner-occurring future intervals are valued more highly than later-occurring future intervals.［6］ This observation has been observed in behavioral economics.［citation needed］

…

［6］MISES, L. V. Human Action. A Treatise on Economics. Scholar's Edition. Alburn: Ludwig von Mises Institute, 1998. Pg. 480

I'm quite familiar with von Mises' views on time preference, I have re-read the cited page, and I really don't see how, or where the inconsistency arises. Neither do I see how the interpretation of the cited page can be deemed correct. If anyone could explain why Mises is cited as being inconsistend I'd be glad to hear the reasons. If, on the other hand, he is not inconsistent, I'd recommend removing or at least modifying the paragraph, because I think diminishing Mises' contribution to time preference theory as defective - although it's not faultless - is misleading.

he is inconsistent? diminishing contribution as defective?(time-incosistencyを不整合という非難と受け取っている?)

真偽の問題ではなく一次文献に頼るのがWikipedia的にダメなので消えている。

しかし、原文にある、人間は近い未来を遠い未来より選好するという話を、双曲割引と誤解したのではという気がする。

ミーゼスが、単独の財の消費を、そもそも区間を持ったものとして扱っていることが誤解を生んでいるかも。

p.480 Human Action (the scholar's edition)

If acting men were not to pay heed to the length of the waiting time, they would never say that a goal is temporally so distant that one cannot consider aiming at it. Faced with the alternative of choosing between two processes of production which render different output with the same input, they would always prefer that process which renders the greater quantity of the same products or better products in the same quantity, even if this result could be attained onIy by lengthening the period of production. Increments in input which result in a more than proportionate increase in the products' duration of serviceableness would unconditionally be deemed advantageous. The fact that men do not act in this way evidences that they value fractions of time of the same length in a different way according as they are nearer or remoter from the instant of the actor's decision. Other things being equal, satisfaction in a nearer period of the future is preferred to satisfaction in a more distant period; disutility is seen in waiting. This fact is already implied in the statement stressed in the opening of this chapter that man distinguishes the time before satisfaction is attained and the time for the duration of which there is satisfaction. If any role at all is played by the time element in human life, there cannot be any question of equal valuation of nearer and remoter periods of the same length. Such an equal valuation would mean that people do not care whether success is attained sooner or later. It would be tantamount to a complete elimination of the time element from the process of valuation.

The mere fact that goods with a longer duration of serviceableness are valued more highly than those with a shorter duration does not yet in itsclf imply a consideration of tine. A roof that can protect a house against the weather during a period of ten years is more valuable than a roof which renders this service only for a period of five years. The quantity of service rendered is different in both cases. But the question which we have to deal with is whether or not an actor in malting his choices attaches to a service to be available in a later period of the future the same value he attaches to a service available at an earlier period.

2. Time Preference as an EssentiaI Requisite of Action

The answer to this question is that acting man does not appraise time periods merely with regard to their dimension. His choices re- garding the removal of future uneasiness are directed by the cate- gories sooner and later. Time for man is not a homogeneous substance of which only length counts. It is not a more or a less in dimension. It is an irreversible flux the fractions of which appear in different perspective according to whether they are nearer to or remoter from the instant of valuation and decision. Satisfaction of a want in the nearer future is, other things being equal, preferred to that in the …

これはただの誤読だと思うけど、Wikipediaでソースの文を繰り返し意図的に誤読して参考文献とする人が問題になったこともあったらしい。