著者
酒井 泰弘
出版者
滋賀大学経済学会
雑誌
彦根論叢 (ISSN:03875989)
巻号頁・発行日
no.第394号, pp.38-57, 2012-12 (Released:2013-01-21)

The main purpose of this paper is to explore the economic thought of Frank H. Knight (1885-1972) with special reference to his ideas of risk and uncertainty. Knight, the “Grand Old Man” of Chicago, is one of the most influential thinker American economics has ever produced. Although hefailed to acquire many faithful followers around himself, we can see some traces of his perspective in the work of Martin Bronfenbrenner(1914-1997), a Chicago Ph.D., with whom I established a close acquaintance at Kobe and Pittsburgh. According to Knight, uncertainty must be taken categorically distinct from the familiar notion of risk. Risk means a quantity susceptible of measurement, so that it is not in effect anuncertainty at all. In contrast, uncertainty is ofthe non-quantity type in the sense that it cannotbe described by any distribution function.It is this “true” uncertainty, and not risk, whichforms the basis of a valid theory of profit. Business decisions deal with situations which are far too unique for any sort of statistical tabulation to have any value of guidance. Such true uncertainty gives the characteristic form of enterprise to economic organization as a whole and accounts for profit or the peculiar income of the entrepreneur. We live in the world of risk and uncertainty.The Great East Japan Earthquake of 11 March 2011 has demonstrated a great lesson against the myth of absolute safety, indicating the necessity of rethinking of presumably “unthinkable events.” We can learn new lessons from old teachings : The legacy of Frank H. Knight is still alive and will remain so throughout the new century.
著者
酒井 泰弘
出版者
Center for Risk Research (CRR), Shiga University
雑誌
CRR Discussion Paper
巻号頁・発行日
no.No. J-36, pp.1-22, 2013-04 (Released:2013-05-02)

The main purpose of this paper is to critically discuss and lucidly compare J. M. Keynes (1883-1946) and F. H. Knight (1886-1972), two towering figures in the history of economic thought. It is in 1921 that they both published apparently similar books on risk, probability and uncertainty. While Knight’contribution on the economics of risk and uncertainty has been well-known and very influential in the economics profession, Keynes’ accomplishments on probability and uncertainty have been more or lessunderestimated in the dark shadow of his most famous book (1936 ) The General Theory of Unemployment, Interest and Money.The present paper aims to focus on an earlier yet equally important book (1921) A Treatise on Probability, hopefully shedding a new light on his outstanding ideas and everlasting influences on his later works including The General Theory. According to Keynes, many probabilities, which are incapable of numerical measurement, can beplaced nevertheless between numerical upper and lower limits. Keynes has demonstrated whether and to what extent animal spirits contributes to the working and performance of the market economy. Remarkably, Keynes' concept of probability anduncertainty can be well-compared to Knight's distinction between a measurable risk and a non-measurable uncertainty. I believe that it is high time for us to unify Keynes and Knight into a new, comprehensive approach to understanding complex human behavior.
著者
酒井 泰弘
出版者
滋賀大学経済学会
雑誌
彦根論叢 (ISSN:03875989)
巻号頁・発行日
no.第398号, pp.50-69, 2013-12 (Released:2014-01-14)

The main purpose of this paper is to criticallydiscuss and lucidly compare J. M. Keynes (1883-1946) and F. H. Knight (1886-1972), two towering figures in the history of economic thought. It is in 1921 that they both published apparently similar books on risk, probability and uncertainty. While Knight’ contribution on the economics of risk and uncertainty has been well-known and very influential in the economics profession, Keynes’accomplishments on probability and uncertainty have been more or less underestimated in the dark shadow of his most famous book (1936) The General Theory of Unemployment, Interest and Money.The present paper aims to focus on an earlieryet equally important book (1921) A Treatise onProbability, hopefully shedding a new light onhis outstanding ideas and everlasting influenceson his later works including The General Theory.According to Keynes, many probabilities, which are incapable of numerical measurement, can be placed nevertheless between numerical upper and lower limits. Keynes has demonstrated whether and to what extent animal spirits contributes to the working and performance of the market economy. Remarkably, Keynes' concept of probability and uncertainty can be well-compared to Knight's distinction between a measurable risk and a non-measurable uncertainty. I believe that it is high time for us to unify Keynes and Knight into a new,comprehensive approach to very complex human behavior.
著者
酒井 泰弘
出版者
Center for Risk Research (CRR), Shiga University
雑誌
CRR Discussion Paper, Series J
巻号頁・発行日
no.No. J-47, pp.1-41, 2014-04 (Released:2014-04-16)

本稿の問題意識の核心はこうである。市場経済のワーキングとパフォーマンスに関して、それを倫理・公平抜きに議論することが妥当であるかどうか、ということである。この点を深く掘り下げるために、先ずマッケンジー、アロー、ドブリューなどの一般均衡論の思考方式を論じる。その背後に潜む独特の美学とイデオロギーについて、詳しく吟味することが重要である。次に、市場均衡の美学に対して、異論を激しく述べてきたフランク・ナイトの考え方を述べる。その中で、競争経済における論理と倫理の関係について、視覚的かつ多角的に私見を開陳したいと思う。私がロチェスター大学にてマッケンジー先生の講義を拝聴していた頃のことである。先生が角谷の不動点定理を用いて、市場均衡解の存在を見事に証明したときに発せられた次の言葉が決して忘れることができないのだ。「おお、実に美しい!」東西冷戦の最中にあって、ソ連式の社会主義システムと米国式の資本主義システムとが激しく覇権を争っていた。厚生経済学の基本定理によれば、市場均衡はパレート最適であり、その逆も真であると言う。まさに、「真・善・美」のカント的世界がこの世に出現したかのようであった。それから40 年。1990 年におけるソ連の崩壊とともに、「経済学の東西冷戦」は終わりを告げた。それとともに、一般均衡論の美学とイデオロギーも次第に霧消していった。だが、旧来の経済学に代わるべき「新しい経済学」の建設も未だ見えない。今こそ、フランク・ナイトの異論に立ち戻り、不確実性と不完全情報の基礎の上に、総合的・学際的社会科学の建設を目指す絶好の機会が訪れていると信じている。
著者
酒井 泰弘
出版者
滋賀大学経済学会
雑誌
彦根論叢 (ISSN:03875989)
巻号頁・発行日
no.第400号, pp.82-105, 2014-06 (Released:2014-07-02)

As the saying goes, we can learn new lessonsfrom old teachings. This paper aims to givecritical assessment of J. M. Keynes (1883-1946)and F. H. Knight (1885-1972), two great economistson probability and uncertainty. It is quiteremarkable to see that there are many contemporariesof outstanding achievement in theKeynes-Knight era: A. Marshall (1842-1924),H. Poincaré (1854-1912), M. Weber (1864-1920), Soseki Natsume (1867-1916), TorahikoTerada (1878-1935), and A. Einstein (1879-1955). While these men are somewhat differentin personality and research field, there is onething in common: They are all deep thinkersof unthinkable phenomena such as bubbles,chance, chaos, complexity, crisis, earthquakes,hazards, and sufferings.In the light of the history of economicthought, we understand that some economistsmay be micro-oriented or macro-orientedwhereas others may be concerned with certaintyor uncertainty. We find it quite convenientto classify all the economists from the time ofAdam Smith to the present day into the followingfour groups. They are:(1)micro andcertainty, (2)macro and certainty, (3)macro anduncertainty, and (4)micro and uncertainty. Inmy opinion, the first group is represented by L.W. McKenzie, an authority in general equilibriumtheory and incidentally my mentor atRochester; and the second one by Karl Marx,the founder of the Marxian school. The thirdgroup is led by J. M. Keynes, perhaps the greatesteconomist of the 20th century and theoriginator of the Keynesian school; and thefourth one by F.H. Knight, the grandfather ofthe original Chicago school.According to Torahiko Terada, a famous scientistand essayist, natural disasters will returnwhen they are out of people’s memory. Likewise,academic geniuses will return before oldheroes are out of our scene. At the beginningof the 21st century, it is quite regrettable thatneither Keynes nor Knight is in sight. We needa Keynes or a Knight in order to establish anew, synthetic social science, thus combiningeconomics, psychology, history, biology, physics,and other related fields.
著者
酒井 泰弘
出版者
滋賀大学経済学会
雑誌
彦根論叢 (ISSN:03875989)
巻号頁・発行日
no.398, pp.50-69, 2013-12

The main purpose of this paper is to criticallydiscuss and lucidly compare J. M. Keynes (1883-1946) and F. H. Knight (1886-1972), two towering figures in the history of economic thought. It is in 1921 that they both published apparently similar books on risk, probability and uncertainty. While Knight' contribution on the economics of risk and uncertainty has been well-known and very influential in the economics profession, Keynes'accomplishments on probability and uncertainty have been more or less underestimated in the dark shadow of his most famous book (1936) The General Theory of Unemployment, Interest and Money.The present paper aims to focus on an earlieryet equally important book (1921) A Treatise onProbability, hopefully shedding a new light onhis outstanding ideas and everlasting influenceson his later works including The General Theory.According to Keynes, many probabilities, which are incapable of numerical measurement, can be placed nevertheless between numerical upper and lower limits. Keynes has demonstrated whether and to what extent animal spirits contributes to the working and performance of the market economy. Remarkably, Keynes' concept of probability and uncertainty can be well-compared to Knight's distinction between a measurable risk and a non-measurable uncertainty. I believe that it is high time for us to unify Keynes and Knight into a new,comprehensive approach to very complex human behavior.
著者
酒井 泰弘
出版者
日本保険学会
雑誌
保険学雑誌 (ISSN:03872939)
巻号頁・発行日
vol.2012, no.619, pp.619_261-619_280, 2012-12-31 (Released:2014-05-08)
参考文献数
47

「天災は忘れた頃に来る」(寺田寅彦の警告)。人間は災害を何度でも忘れ,愚行を何回でも繰り返す。従来において原発のリスク分析はおおむね低調であったが,フランク・ナイト(1885-1972)のように,「想定外」の事象を積極的に研究する学者も存在した。福島原発事故に関して言えば,ナイトなら地震大国・日本に多数の原発を建設することは,本来計量化できない「不確実性」であると思量したはずである。ところが現実には,「安全神話」に寄りかかり,それを計量可能な「リスク」であると即断してしまったようだ。思うに,今や「新しい総合リスク学」を樹立することが喫緊の課題である。そのためには第一に,社会心理学の成果を取り入れて,「怖いリスク」や「未知のリスク」など,リスクの「質」の違いを考慮しなければならない。第二に,経済物理学の展開に依拠して,(平均や分散などの統計数量が無意味なものとなる)「べき分布」の活用を図らなければならない。
著者
久保 英也 酒井 泰弘 前田 祐治
出版者
滋賀大学
雑誌
基盤研究(C)
巻号頁・発行日
2008

大数の法則で事故率を安定させその平均値から保険料を計算するという伝統的な保険料の算出方法ではなく、モンテカルロ・シミュレーションにより、保険市場と資本市場の狭間にある生命保険の買取制度の取引価格やキャプティブ保険会社の損害保険料、ファイナイトの保険料などを算出することができた。保険機能のすべてを資本市場が代替することはないが、資本市場が保険リスクを引受けることで保険市場自体も拡大する分野がある。ただし、生命保険の資本市場化は人の命を市場で売買することでもあり、その倫理性の担保が求められる。