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'''Econophysics''' is a heterodox interdisciplinary research field, applying theories and methods originally developed by [[Physics|physicists]] in order to solve problems in [[economics]], usually those including uncertainty or [[stochastic process]]es and [[Chaos theory|nonlinear dynamics]]. Some of its application to the study of financial markets has also been termed [[statistical finance]] referring to its roots in [[statistical physics]]. Econophysics is closely related to [[social physics]].

'''Econophysics''' is a [[Heterodox economics|heterodox]] interdisciplinary research field, applying theories and methods originally developed by [[Physics|physicists]] in order to solve problems in [[economics]], usually those including uncertainty or [[stochastic process]]es and [[Chaos theory|nonlinear dynamics]]. Some of its application to the study of financial markets has also been termed [[statistical finance]] referring to its roots in [[statistical physics]]. Econophysics is closely related to [[social physics]].

Econophysics is a heterodox interdisciplinary research field, applying theories and methods originally developed by physicists in order to solve problems in economics, usually those including uncertainty or stochastic processes and nonlinear dynamics. Some of its application to the study of financial markets has also been termed statistical finance referring to its roots in statistical physics. Econophysics is closely related to social physics.

Econophysics is a heterodox interdisciplinary research field, applying theories and methods originally developed by physicists in order to solve problems in economics, usually those including uncertainty or stochastic processes and nonlinear dynamics. Some of its application to the study of financial markets has also been termed statistical finance referring to its roots in statistical physics. Econophysics is closely related to social physics.

Physicists' interest in the [[social sciences]] is not new; [[Daniel Bernoulli]], as an example, was the originator of [[utility]]-based preferences. One of the founders of [[neoclassical economic theory]], former Yale University Professor of Economics [[Irving Fisher]], was originally trained under the renowned Yale [[physicist]], [[Josiah Willard Gibbs]].<ref>[http://www.yaleeconomicreview.com/issues/2006_spring/financephysical.html Yale Economic Review, Retrieved October-25-09] {{webarchive|url=https://web.archive.org/web/20080508025252/http://www.yaleeconomicreview.com/issues/2006_spring/financephysical.html |date=2008-05-08 }}</ref> Likewise, [[Jan Tinbergen]], who won the first [[Nobel Memorial Prize in Economic Sciences]] in 1969 for having developed and applied dynamic models for the analysis of economic processes, studied physics with [[Paul Ehrenfest]] at [[Leiden University]]. In particular, Tinbergen developed the [[Gravity model of trade|gravity model of international trade]] that has become the workhorse of international economics.

Physicists' interest in the [[social sciences]] is not new; [[Daniel Bernoulli]], as an example, was the originator of [[utility]]-based preferences. One of the founders of [[neoclassical economic theory]], former Yale University Professor of Economics [[Irving Fisher]], was originally trained under the renowned Yale [[physicist]], [[Josiah Willard Gibbs]].<ref>[http://www.yaleeconomicreview.com/issues/2006_spring/financephysical.html Yale Economic Review, Retrieved October-25-09] {{webarchive|url=https://web.archive.org/web/20080508025252/http://www.yaleeconomicreview.com/issues/2006_spring/financephysical.html |date=2008-05-08 }}</ref> Likewise, [[Jan Tinbergen]], who won the first [[Nobel Memorial Prize in Economic Sciences]] in 1969 for having developed and applied dynamic models for the analysis of economic processes, studied physics with [[Paul Ehrenfest]] at [[Leiden University]]. In particular, Tinbergen developed the [[Gravity model of trade|gravity model of international trade]] that has become the workhorse of international economics.

Physicists' interest in the social sciences is not new; Daniel Bernoulli, as an example, was the originator of utility-based preferences. One of the founders of neoclassical economic theory, former Yale University Professor of Economics Irving Fisher, was originally trained under the renowned Yale physicist, Josiah Willard Gibbs. Likewise, Jan Tinbergen, who won the first Nobel Memorial Prize in Economic Sciences in 1969 for having developed and applied dynamic models for the analysis of economic processes, studied physics with Paul Ehrenfest at Leiden University. In particular, Tinbergen developed the gravity model of international trade that has become the workhorse of international economics.

Physicists' interest in the social sciences is not new; Daniel Bernoulli, as an example, was the originator of utility-based preferences. One of the founders of neoclassical economic theory, former Yale University Professor of Economics Irving Fisher, was originally trained under the renowned Yale physicist, Josiah Willard Gibbs.

物理学家对社会科学的兴趣并不是什么新鲜事; 例如，丹尼尔·伯努利就是基于效用的偏好的鼻祖。新古典主义经济理论的创始人之一，前耶鲁大学经济学教授 Irving Fisher，最初受训于著名的耶鲁大学物理学家约西亚·威拉德·吉布斯。同样，Jan Tinbergen，因为开发和应用经济过程分析的动力学模型而获得1969年诺贝尔经济学奖，在莱顿大学和 Paul Ehrenfest 一起学习物理学。特别是，廷伯根发展了国际贸易的引力模型，这个模型已经成为国际经济学的主力。

物理学家对社会科学的兴趣并不是什么新鲜事; 例如，丹尼尔·伯努利就是基于效用的偏好的鼻祖。新古典主义经济理论的创始人之一，前耶鲁大学经济学教授 Irving Fisher，最初受训于著名的耶鲁大学物理学家约西亚·威拉德·吉布斯。

Econophysics was started in the mid-1990s by several physicists working in the subfield of [[statistical mechanics]].  Unsatisfied with the traditional explanations and approaches of economists – which usually prioritized simplified approaches for the sake of soluble theoretical models over agreement with empirical data – they applied tools and methods from physics, first to try to match financial data sets, and then to explain more general economic phenomena.

Econophysics was started in the mid-1990s by several physicists working in the subfield of [[statistical mechanics]].  Unsatisfied with the traditional explanations and approaches of economists – which usually prioritized simplified approaches for the sake of soluble theoretical models over agreement with empirical data – they applied tools and methods from physics, first to try to match financial data sets, and then to explain more general economic phenomena.

One driving force behind econophysics arising at this time was the sudden availability of large amounts of financial data, starting in the 1980s.  It became apparent that traditional methods of analysis were insufficient – standard economic methods dealt with homogeneous agents and equilibrium, while many of the more interesting phenomena in financial markets fundamentally depended on [[Heterogeneous agents#Social and human science|heterogeneous agents]] and far-from-equilibrium situations.

One driving force behind econophysics arising at this time was the sudden availability of large amounts of financial data, starting in the 1980s.  It became apparent that traditional methods of analysis were insufficient – standard economic methods dealt with homogeneous agents and equilibrium, while many of the more interesting phenomena in financial markets fundamentally depended on [[Heterogeneous agents#Social and human science|heterogeneous agents]] and far-from-equilibrium situations.

One driving force behind econophysics arising at this time was the sudden availability of large amounts of financial data, starting in the 1980s. It became apparent that traditional methods of analysis were insufficient – standard economic methods dealt with homogeneous agents and equilibrium, while many of the more interesting phenomena in financial markets fundamentally depended on heterogeneous agents and far-from-equilibrium situations.

Papers on econophysics have been published primarily in journals devoted to physics and statistical mechanics, rather than in leading economics journals. Some Mainstream economists have generally been unimpressed by this work.&nbsp; It appears that it also plays a role that near a change of the tendency (e.g. from falling to rising prices) there are typical "panic reactions" of the selling or buying agents with algebraically increasing bargain rapidities and volumes.&nbsp; The "fat tails" are also observed in commodity markets.

The term "econophysics" was coined by [[H. Eugene Stanley]], to describe the large number of papers written by physicists in the problems of (stock and other) markets, in a conference on statistical physics in [[Kolkata]] (erstwhile [[Calcutta]])  in 1995 and first appeared in its proceedings publication in [[Physica A]] 1996.<ref>[http://www.saha.ac.in/cmp/camcs/Stanley-interview.pdf  Interview of H. E. Stanley on Econophysics (Published in "IIM Kozhikode Society & Management Review", Sage publication (USA), Vol. 2 Issue 2 (July), pp. 73-78 (2013))]</ref><ref>[https://arxiv.org/pdf/1308.2191.pdf Econophysics Research in India in the last two Decades (1993-2013) (Published in "IIM Kozhikode Society & Management Review", Sage publication (USA), Vol. 2 Issue 2 (July), pp. 135-146 (2013))]</ref> The inaugural meeting on econophysics was organised in 1998 in Budapest by [[János Kertész]] and [[Imre Kondor]]. The first book on econophysics was by R. N. Mantegna & H. E. Stanley in  2000.<ref>"An Introduction to Econophysics", Cambridge University Press, Cambridge (2000)</ref>

The term "econophysics" was coined by [[H. Eugene Stanley]], to describe the large number of papers written by physicists in the problems of (stock and other) markets, in a conference on statistical physics in [[Kolkata]] (erstwhile [[Calcutta]])  in 1995 and first appeared in its proceedings publication in [[Physica A]] 1996.<ref>[http://www.saha.ac.in/cmp/camcs/Stanley-interview.pdf  Interview of H. E. Stanley on Econophysics (Published in "IIM Kozhikode Society & Management Review", Sage publication (USA), Vol. 2 Issue 2 (July), pp. 73-78 (2013))]</ref><ref>[https://arxiv.org/abs/1308.2191 Econophysics Research in India in the last two Decades (1993-2013) (Published in "IIM Kozhikode Society & Management Review", Sage publication (USA), Vol. 2 Issue 2 (July), pp. 135-146 (2013))]</ref> The inaugural meeting on econophysics was organised in 1998 in Budapest by [[János Kertész]] and [[Imre Kondor]]. The first book on econophysics was by R. N. Mantegna & H. E. Stanley in  2000.<ref>"An Introduction to Econophysics", Cambridge University Press, Cambridge (2000)</ref>

The term "econophysics" was coined by H. Eugene Stanley, to describe the large number of papers written by physicists in the problems of (stock and other) markets, in a conference on statistical physics in Kolkata (erstwhile Calcutta)  in 1995 and first appeared in its proceedings publication in Physica A 1996. The inaugural meeting on econophysics was organised in 1998 in Budapest by János Kertész and Imre Kondor. The first book on econophysics was by R. N. Mantegna & H. E. Stanley  in  2000.

As in quantum field theory the "fat tails" can be obtained by complicated "nonperturbative" methods, mainly by numerical ones, since they contain the deviations from the usual Gaussian approximations, e.g. the Black–Scholes theory.  Fat tails can, however, also be due to other phenomena, such as a random number of terms in the central-limit theorem, or any number of other, non-econophysics models. Due to the difficulty in testing such models, they have received less attention in traditional economic analysis.

The almost regular meeting series on the topic include: ECONOPHYS-KOLKATA (held in Kolkata & Delhi),<ref>"Econophysics of Wealth Distributions", Eds. A. Chatterjee et al., New Economic Windows, Springer, Milan (2005), & the subsequent eight Proc. Volumes published in  2006, 2007, 2010, 2011, 2013, 2014, 2015 & 2019 in the New Economic Windows series of Springer</ref> Econophysics Colloquium, ESHIA/ WEHIA.

The almost regular meeting series on the topic include: ECONOPHYS-KOLKATA (held in Kolkata & Delhi),<ref>"Econophysics of Wealth Distributions", Eds. A. Chatterjee et al., New Economic Windows, Springer, Milan (2005), & the subsequent eight Proc. Volumes published in  2006, 2007, 2010, 2011, 2013, 2014, 2015 & 2019 in the New Economic Windows series of Springer</ref> Econophysics Colloquium, ESHIA/ WEHIA.

In recent years [[network science]], heavily reliant on analogies from [[statistical mechanics]], has been applied to the study of productive systems. That is the case with the works done at the [[Santa Fe Institute]] in European Funded Research Projects as Forecasting Financial Crises and the Harvard-MIT [[The Observatory of Economic Complexity|Observatory of Economic Complexity]]

In recent years [[network science]], heavily reliant on analogies from [[statistical mechanics]], has been applied to the study of productive systems. That is the case with the works done at the [[Santa Fe Institute]] in European Funded Research Projects as Forecasting Financial Crises and the Harvard-MIT [[The Observatory of Economic Complexity|Observatory of Economic Complexity]]

If "econophysics" is taken to denote the principle of applying statistical mechanics to economic analysis, as opposed to a particular literature or network, priority of innovation is probably due to Emmanuel Farjoun and [[Moshé Machover]] (1983). Their book ''Laws of Chaos: A Probabilistic Approach to Political Economy'' proposes ''dis''solving (their words) the [[transformation problem]] in Marx's political economy by re-conceptualising the relevant quantities as random variables.<ref>Farjoun and Machover disclaim complete originality: their book is dedicated to the late  Robert H. Langston, who they cite for direct inspiration (page 12), and they also note an independent suggestion in a discussion paper by [[Edwin Thompson Jaynes|E.T. Jaynes]] (page 239)</ref>

If "econophysics" is taken to denote the principle of applying statistical mechanics to economic analysis, as opposed to a particular literature or network, priority of innovation is probably due to Emmanuel Farjoun and [[Moshé Machover]] (1983). Their book ''Laws of Chaos: A Probabilistic Approach to Political Economy'' proposes ''dis''solving (their words) the [[transformation problem]] in Marx's political economy by re-conceptualising the relevant quantities as random variables.<ref>Farjoun and Machover disclaim complete originality: their book is dedicated to the late  Robert H. Langston, who they cite for direct inspiration (page 12), and they also note an independent suggestion in a discussion paper by [[Edwin Thompson Jaynes|E.T. Jaynes]] (page 239)</ref>

If, on the other hand, "econophysics" is taken to denote the application of physics to

If, on the other hand, "econophysics" is taken to denote the application of physics to

economics, one can consider the works of [[Léon Walras]] and [[Vilfredo Pareto]] as part of it. Indeed, as shown by [[Bruna Ingrao]] and [[Giorgio Israel]], [[general equilibrium theory]] in economics is based on the physical concept of [[mechanical equilibrium]].

economics, one can consider the works of [[Léon Walras]] and [[Vilfredo Pareto]] as part of it. Indeed, as shown by [[Bruna Ingrao]] and [[Giorgio Israel]], [[general equilibrium theory]] in economics is based on the physical concept of [[mechanical equilibrium]].

经济物理学与 Ian Steedman 和其他与新李嘉图学派相关的人提出的经济学的物理量方法没有任何关系。Notable econophysicists are Jean-Philippe Bouchaud, Bikas K Chakrabarti, J. Doyne Farmer, Diego Garlaschelli, Dirk Helbing, János Kertész, Francis Longstaff, Rosario N. Mantegna, Matteo Marsili, Joseph L. McCauley, Enrico Scalas, Didier Sornette, H. Eugene Stanley, Victor Yakovenko and Yi-Cheng Zhang.在经济物理学的正规课程中，特别值得一提的是莱顿大学物理系的 Diego Garlaschelli 开设的一门课程，他就是第一位诺贝尔经济学奖得主 Jan Tinbergen 的出身。由2014年9月起，英皇书院荣获 Econophysics 首个全职教授职位。

Econophysics has nothing to do with the "physical quantities approach" to economics, advocated by [[Ian Steedman]] and others associated with [[neo-Ricardianism]]. Notable econophysicists are [[Jean-Philippe Bouchaud]], [[Bikas K Chakrabarti]], [[J. Doyne Farmer]], [[Diego Garlaschelli]], [[Dirk Helbing]], [[János Kertész]], [[Francis Longstaff]], [[Rosario N. Mantegna]], Matteo Marsili, [[Joseph L. McCauley]], Enrico Scalas, [[Didier Sornette]], [[H. Eugene Stanley]], [[Victor Yakovenko]] and Yi-Cheng Zhang. Particularly noteworthy among the formal courses on econophysics is the one offered by [[Diego Garlaschelli]] at the Physics Department of the [[Leiden University]],<ref>{{Cite web|url=https://studiegids.leidenuniv.nl/en/courses/show/34804/econofysica|title=Econophysics, 2012-2013 ~ e-Prospectus, Leiden University|website=studiegids.leidenuniv.nl|language=en|access-date=2018-09-10}}</ref><ref>{{Cite web|url=https://studiegids.universiteitleiden.nl/courses/99643/econophysics|title=Econophysics, 2020-2021 ~ e-Prospectus, Leiden University|website=studiegids.leidenuniv.nl|language=en|access-date=2020-09-05}}</ref> from where the first Nobel-laureate in economics [[Jan Tinbergen]] came. From September 2014 King's College has awarded the first position of Full Professor in Econophysics.

Basic tools of econophysics are [[Probability|probabilistic]] and [[Statistics|statistical]] methods often taken from statistical physics.

Basic tools of econophysics are [[Probability|probabilistic]] and [[Statistics|statistical]] methods often taken from statistical physics.

Physics models that have been applied in economics include the [[kinetic theory of gas]] (called the [[kinetic exchange models of markets]] <ref>{{cite book| author=[[Bikas K Chakrabarti]], Anirban Chakraborti, Satya R Chakravarty, Arnab Chatterjee |title=Econophysics of Income & Wealth Distributions | publisher=[[Cambridge University Press]], [[Cambridge]]|year= 2012 |work=}}</ref>), [[percolation]] models, [[Chaos theory|chaotic]] models developed to study cardiac arrest, and models with [[self-organizing criticality]] as well as other models developed for [[earthquake prediction]].<ref>{{cite book |author=Didier Sornette |title=Why Stock Markets Crash? |publisher=[[Princeton University Press]]|year= 2003 |accessdate=|work=|author-link=Didier Sornette }}</ref> Moreover, there have been attempts to use the mathematical theory of [[complexity]] and [[information theory]], as developed by many scientists among whom are [[Murray Gell-Mann]] and [[Claude E. Shannon]], respectively.

Physics models that have been applied in economics include the [[kinetic theory of gas]] (called the [[kinetic exchange models of markets]] <ref>{{cite book| author=[[Bikas K Chakrabarti]], Anirban Chakraborti, Satya R Chakravarty, Arnab Chatterjee |title=Econophysics of Income & Wealth Distributions | publisher=[[Cambridge University Press]], [[Cambridge]]|year= 2012 |work=}}</ref>), [[percolation]] models, [[Chaos theory|chaotic]] models developed to study cardiac arrest, and models with [[self-organizing criticality]] as well as other models developed for [[earthquake prediction]].<ref>{{cite book |author=Didier Sornette |title=Why Stock Markets Crash? |publisher=[[Princeton University Press]]|year= 2003 |accessdate=|work=|author-link=Didier Sornette }}</ref> Moreover, there have been attempts to use the mathematical theory of [[complexity]] and [[information theory]], as developed by many scientists among whom are [[Murray Gell-Mann]] and [[Claude E. Shannon]], respectively.

Here the demand is increasing, as with [[Veblen good]]s or stock buyers with the [[Hot-hand fallacy#Consumers|"hot hand"]] fallacy preferring to buy more successful stocks and sell those that are less successful.

For [[Potential game#Bounded Rational Models|potential games]], it has been shown that an emergence-producing equilibrium based on information via Shannon information entropy produces the same equilibrium measure ([[Gibbs measure]] from statistical mechanics) as a stochastic dynamical equation, both of which are based on [[bounded rationality]] models used by economists.<ref name="Ca">{{cite arXiv |last=Campbell |first=Michael J. |date=2005 |title=A Gibbsian approach to potential game theory |eprint=cond-mat/0502112v2 | url=https://www.researchgate.net/publication/1878148}}</ref> 

Here the demand is increasing, as with Veblen goods or stock buyers with the "hot hand" fallacy preferring to buy more successful stocks and sell those that are less successful.

The fluctuation-dissipation theorem connects the two to establish a concrete correspondence of "temperature", "entropy", "free potential/energy", and other physics notions to an economics system.  The statistical mechanics model is not constructed a-priori - it is a result of a boundedly rational assumption and modeling on existing neoclassical models.  It has been used to prove the "inevitability of collusion" result of [[Huw Dixon]] in a case for which the neoclassical version of the model does not predict collusion.<ref name="HD">{{cite journal | last = Dixon | first = Huw| title = keeping up with the Joneses: competition and the evolution of collusion| journal = Journal of Economic Behavior and Organization| volume = 43| issue = 2| pages = 223–238| date = 2000| doi=10.1016/s0167-2681(00)00117-7}}</ref> 

这里的需求正在增加，就像 Veblen 的产品或有“热手”谬论的股票买家，他们更愿意买入更多成功的股票，卖出那些不那么成功的股票。

Here the demand is increasing, as with [[Veblen good]]s or stock buyers with the [[Hot-hand fallacy#Consumers|"hot hand"]] fallacy preferring to buy more successful stocks and sell those that are less successful.<ref name="Johnson2005">

<ref name="Johnson2005">

{{cite journal|last=Johnson|first=Joseph|author2=Tellis, G.J. |author3=Macinnis, D.J. |s2cid=145211986|title=Losers, Winners, and Biased Trades|journal=Journal of Consumer Research|year=2005|volume=2|issue=32|pages=324–329|doi=10.1086/432241}}</ref>

<ref name="Johnson2005">

[[Vernon L. Smith]] used these techniques to model sociability in economics.<ref name = "CaSm">

</ref>

Quantifiers derived from [[information theory]] were used in several papers by econophysicist [http://www.aureliofernandez.net/ Aurelio F. Bariviera] and coauthors in order to assess the degree in the informational efficiency of stock markets.<ref>{{cite journal |author=Zunino, L., Bariviera, A.F., Guercio, M.B., Martinez, L.B. and Rosso, O.A.|title=On the efficiency of sovereign bond markets |journal=Physica A: Statistical Mechanics and Its Applications|volume= 391|pages= 4342–4349|year=2012 |doi=10.1016/j.physa.2012.04.009 | issue = 18|bibcode = 2012PhyA..391.4342Z |url=http://ri.conicet.gov.ar/bitstream/11336/59368/11/CONICET_Digital_Nro.2499931a-041e-4174-8911-3017a0595f19_J.pdf|hdl=11336/59368 |s2cid=122129979 }}</ref>

经济物理学家[ http://www.aureliofernandez.net/ · 奥雷里奥 · 巴里维埃拉]和合著者在几篇论文中使用了来自信息论的量词来评估股票市场信息效率的程度。在 Physica 发表的一篇论文中

Another good example is [[random matrix theory]], which can be used to identify the noise in financial correlation matrices.  One paper has argued that this technique can improve the performance of portfolios, e.g., in applied in [[Modern portfolio theory|portfolio optimization]].<ref>{{cite journal |author1=Vasiliki Plerou |author2=Parameswaran Gopikrishnan |author3=Bernd Rosenow |author4=Luis Amaral |author5=Thomas Guhr |author6=H. Eugene Stanley |title=Random matrix approach to cross correlations in financial data |journal=Physical Review E|volume= 65|page= 066126 |year=2002 |doi=10.1103/PhysRevE.65.066126 |pmid=12188802 | issue = 6|arxiv = cond-mat/0108023 |bibcode = 2002PhRvE..65f6126P |s2cid=2753508 }}</ref>

There are, however, various other tools from physics that have so far been used, such as [[fluid dynamics]], [[classical mechanics]] and [[quantum mechanics]] (including so-called [[classical economy]], [[quantum economics]] and [[quantum finance]]),<ref name="AK">{{Cite book|title = Probabilistic Economic Theory|last = Anatoly V. Kondratenko|work = Nauka |year = 2015|isbn = 978-5-02-019121-1}}</ref> and the [[path integral formulation]] of statistical mechanics.<ref name=":0">{{Cite book|title = The Unity of Science and Economics: A New Foundation of Economic Theory|last = Chen|first = Jing|publisher = Springer|year = 2015|isbn = |location = https://www.springer.com/us/book/9781493934645|pages = }}</ref>

 

 

 

 

 

 

 

 

 

 

There are, however, various other tools from physics that have so far been used, such as [[fluid dynamics]], [[classical mechanics]] and [[quantum mechanics]] (including so-called [[classical economy]], [[quantum economics]] and [[quantum finance]]),<ref name="AK">{{Cite book|title = Probabilistic Economic Theory|last = Anatoly V. Kondratenko|publisher = "Nauka" |year = 2015|isbn = 978-5-02-019121-1}}</ref> and the [[path integral formulation]] of statistical mechanics.<ref name=":0">{{Cite book|title = The Unity of Science and Economics: A New Foundation of Economic Theory|last = Chen|first = Jing|publisher = Springer|year = 2015|isbn = |location = https://www.springer.com/us/book/9781493934645|pages = }}</ref>

 

 

The concept of [[economic complexity index]], introduced by the MIT physicist [[Cesar A. Hidalgo]] and the Harvard economist [[Ricardo Hausmann]] and made available at MIT's [[The Observatory of Economic Complexity|Observatory of Economic Complexity]], has been devised as a [[List of countries by future GDP (based on ECI) estimates|predictive tool for economic growth]]. According to the estimates of Hausmann and Hidalgo, the ECI is far more accurate in predicting GDP growth than the traditional governance measures of the [[World Bank]].<ref>{{cite web |url=http://atlas.media.mit.edu/atlas/ |title= The Atlas of Economic Complexity |author1=Ricardo Hausmann |author2=Cesar Hidalgo |publisher= The Observatory of Economic Complexity (MIT Media Lab) |accessdate=26 April 2012|display-authors=etal}}</ref>

The concept of [[economic complexity index]], introduced by the MIT physicist [[Cesar A. Hidalgo]] and the Harvard economist [[Ricardo Hausmann]] and made available at MIT's [[The Observatory of Economic Complexity|Observatory of Economic Complexity]], has been devised as a [[List of countries by future GDP (based on ECI) estimates|predictive tool for economic growth]]. According to the estimates of Hausmann and Hidalgo, the ECI is far more accurate in predicting GDP growth than the traditional governance measures of the [[World Bank]].<ref>{{cite web |url=http://atlas.media.mit.edu/atlas/ |title= The Atlas of Economic Complexity |author1=Ricardo Hausmann |author2=Cesar Hidalgo |publisher= The Observatory of Economic Complexity (MIT Media Lab) |accessdate=26 April 2012|display-authors=etal}}</ref>

在金融理论和扩散理论之间也有相似之处。例如，期权定价的布莱克-斯科尔斯方程是一个扩散-对流方程(见对布莱克-斯科尔斯方法论的批判)。布莱克-斯科尔斯理论可以扩展为经济活动中主要因素的分析理论。

There are also analogies between finance theory and [[diffusion]] theory. For instance, the [[Black–Scholes equation]] for [[option (finance)|option]] pricing is a [[diffusion equation|diffusion]]-[[advection]] equation (see however <ref name="autogenerated2003">{{cite book |author1=Jean-Philippe Bouchaud |author2=Marc Potters |title=Theory of Financial Risk and Derivative Pricing |url=https://archive.org/details/theoryoffinancia0000bouc |url-access=registration |publisher=Cambridge University Press|year= 2003 |accessdate=|work=}}</ref><ref>{{cite journal|doi=10.1080/713665871 | volume=1 | issue=5 | title=Welcome to a non-Black-Scholes world | year=2001 | journal=Quantitative Finance | pages=482–483 | last1 = Bouchaud | first1 = J-P. | last2 = Potters | first2 = M.| s2cid=154368053 }}</ref> for a critique of the Black–Scholes methodology). The Black–Scholes theory can be extended to provide an analytical theory of main factors in economic activities.<ref name=":0" />

Papers on econophysics have been published primarily in journals devoted to physics and statistical mechanics, rather than in leading economics journals. [[Mainstream economics|Mainstream economists]] have generally been unimpressed by this work.<ref>{{cite journal |author=Philip Ball |title=Econophysics: Culture Crash |journal=Nature |volume=441 |pages=686–688 |year=2006 |doi=10.1038/441686a |pmid=16760949 |issue=7094|bibcode = 2006Natur.441..686B |citeseerx=10.1.1.188.8120 }}</ref> Some economists, including [[Mauro Gallegati]], [[Steve Keen]], [[Paul Ormerod]], and Alan Kirman have shown more interest, but also criticized some trends in econophysics.

Papers on econophysics have been published primarily in journals devoted to physics and statistical mechanics, rather than in leading economics journals. Some [[Mainstream economics|Mainstream economists]] have generally been unimpressed by this work.<ref>{{cite journal |author=Philip Ball |title=Econophysics: Culture Crash |journal=Nature |volume=441 |pages=686–688 |year=2006 |doi=10.1038/441686a |pmid=16760949 |issue=7094|bibcode = 2006Natur.441..686B |citeseerx=10.1.1.188.8120 |s2cid=4319192 }}</ref> Other economists, including [[Mauro Gallegati]], [[Steve Keen]], [[Paul Ormerod]], and Alan Kirman have shown more interest, but also criticized some trends in econophysics. More recently, [[Vernon L. Smith]], one of the founders of [[experimental economics]] and [[Nobel Memorial Prize in Economic Sciences]] laureate, has used these techniques and claimed they show a lot of promise.<ref name = CaSm></ref> 

 

Papers on econophysics have been published primarily in journals devoted to physics and statistical mechanics, rather than in leading economics journals. Mainstream economists have generally been unimpressed by this work. Some economists, including Mauro Gallegati, Steve Keen, Paul Ormerod, and Alan Kirman have shown more interest, but also criticized some trends in econophysics.

 

Econophysics is having some impacts on the more applied field of [[quantitative finance]], whose scope and aims significantly differ from those of economic theory. Various econophysicists have introduced models for price fluctuations in [[physics of financial markets]] or original points of view on established models.<ref name="autogenerated2003"/><ref>{{cite journal |author=Enrico Scalas |title=The application of continuous-time random walks in finance and economics |journal=Physica A |volume=362 |pages=225–239 |year=2006 |doi=10.1016/j.physa.2005.11.024|bibcode = 2006PhyA..362..225S |issue=2 }}</ref><ref>{{cite journal |author1=Y. Shapira |author2=Y. Berman |author3=E. Ben-Jacob |title=Modelling the short term herding behaviour of stock markets |journal=New Journal of Physics |volume=16 |issue=5 |year=2014 | doi= 10.1088/1367-2630/16/5/053040|bibcode = 2014NJPh...16e3040S |page=053040|doi-access=free }}</ref> Also several scaling laws have been found in various economic data.<ref>{{cite journal |author1=Y. Liu |author2=P. Gopikrishnan |author3=P. Cizeau |author4=M. Meyer |author5=C.-K. Peng |author6=H. E. Stanley |title=Statistical properties of the volatility of price fluctuations |year=1999| journal=[[Physical Review E]]| volume=60| issue=2|pages=1390–400 | doi= 10.1103/PhysRevE.60.1390|pmid=11969899 |arxiv = cond-mat/9903369 |bibcode = 1999PhRvE..60.1390L |citeseerx=10.1.1.241.9346 |s2cid=7512788 }}</ref><ref>{{cite journal |author1=M. H. R. Stanley |author2=L. A. N. Amaral |author3=S. V. Buldyrev |author4=S. Havlin |author5=H. Leschhorn |author6=P. Maass |author7=M. A. Salinger |author8=H. E. Stanley |title=Scaling behaviour in the growth of companies  |journal=Nature |volume=379 |page=804 |year=1996| url=http://havlin.biu.ac.il/Publications.php?keyword=Scaling+behaviour+in+the+growth+of+companies&year=*&match=all |doi=10.1038/379804a0 |issue=6568|bibcode = 1996Natur.379..804S |s2cid=4361375 }}</ref><ref>{{cite journal |author1=K. Yamasaki |author2=L. Muchnik |author3=S. Havlin |author4=A. Bunde |author5=H.E. Stanley |title=Scaling and memory in volatility return intervals in financial markets |journal=PNAS |volume=102 |pages=9424–8  |year=2005| url=http://havlin.biu.ac.il/Publications.php?keyword=Scaling+and+memory+in+volatility+return+intervals+in+financial+markets&year=*&match=all |doi=10.1073/pnas.0502613102 |pmid=15980152 |issue=26 |pmc=1166612|bibcode = 2005PNAS..102.9424Y }}</ref>

In contrast, econophysics is having some impact on the more applied field of [[quantitative finance]], whose scope and aims significantly differ from those of economic theory. Various econophysicists have introduced models for price fluctuations in [[financial markets]] or original points of view on established models.<ref name="autogenerated2003"/><ref>{{cite journal |author=Enrico Scalas |title=The application of continuous-time random walks in finance and economics |journal=Physica A |volume=362 |pages=225–239 |year=2006 |doi=10.1016/j.physa.2005.11.024|bibcode = 2006PhyA..362..225S |issue=2 }}</ref><ref>{{cite journal |author1=Y. Shapira |author2=Y. Berman |author3=E. Ben-Jacob |title=Modelling the short term herding behaviour of stock markets |journal=New Journal of Physics |volume=16 |issue=5 |year=2014 | doi= 10.1088/1367-2630/16/5/053040|bibcode = 2014NJPh...16e3040S |page=053040|doi-access=free }}</ref> Also several scaling laws have been found in various economic data.<ref>{{cite journal |author1=Y. Liu |author2=P. Gopikrishnan |author3=P. Cizeau |author4=M. Meyer |author5=C.-K. Peng |author6=H. E. Stanley |title=Statistical properties of the volatility of price fluctuations |year=1999| journal=[[Physical Review E]]| volume=60| issue=2| page=1390| doi= 10.1103/PhysRevE.60.1390|arxiv = cond-mat/9903369 |bibcode = 1999PhRvE..60.1390L |citeseerx=10.1.1.241.9346 }}</ref><ref>{{cite journal |author1=M. H. R. Stanley |author2=L. A. N. Amaral |author3=S. V. Buldyrev |author4=S. Havlin |author5=H. Leschhorn |author6=P. Maass |author7=M. A. Salinger |author8=H. E. Stanley |title=Scaling behaviour in the growth of companies  |journal=Nature |volume=379 |page=804 |year=1996| url=http://havlin.biu.ac.il/Publications.php?keyword=Scaling+behaviour+in+the+growth+of+companies&year=*&match=all |doi=10.1038/379804a0 |issue=6568|bibcode = 1996Natur.379..804S }}</ref><ref>{{cite journal |author1=K. Yamasaki |author2=L. Muchnik |author3=S. Havlin |author4=A. Bunde |author5=H.E. Stanley |title=Scaling and memory in volatility return intervals in financial markets |journal=PNAS |volume=102 |pages=9424–8  |year=2005| url=http://havlin.biu.ac.il/Publications.php?keyword=Scaling+and+memory+in+volatility+return+intervals+in+financial+markets&year=*&match=all |doi=10.1073/pnas.0502613102 |pmid=15980152 |issue=26 |pmc=1166612|bibcode = 2005PNAS..102.9424Y }}</ref>

 

 

==Main results==

==Main results==

Presently, one of the main results of econophysics comprises the explanation of the [[Fat-tailed distribution|"fat tails"]] in the distribution of many kinds of financial data as a [[Universality class|universal]] self-similar [[scaling invariance|scaling]] property (i.e. scale invariant over many orders of magnitude in the data),<ref>The physicists noted the scaling behaviour of "fat tails" through a letter to the scientific journal ''[[Nature (journal)|Nature]]'' by Rosario N. Mantegna and H. Eugene Stanley: ''Scaling behavior in the dynamics of an economic index'', Nature Vol. 376, pages 46-49 (1995)</ref> arising from the tendency of individual market competitors, or of aggregates of them, to exploit systematically and optimally the prevailing "microtrends" (e.g., rising or falling prices). These "fat tails" are not only mathematically important, because they comprise the  [[risk]]s, which may be on the one hand, very small such that one may tend to neglect them, but which - on the other hand - are not negligible at all, i.e. they can never be made exponentially tiny, but instead follow a measurable algebraically decreasing power law, for example with a ''failure probability'' of only <math>P\propto x^{-4}\,,</math> where ''x'' is an increasingly large variable  in the tail region of the distribution considered (i.e. a price statistics with much more than 10⁸ data). I.e., the events considered are not simply "outliers" but must really be taken into account and cannot be "insured away".<ref name="Preis" />&nbsp; It appears that it also plays a role that near a change of the tendency (e.g. from falling to rising prices) there are typical "panic reactions" of the selling or buying agents with algebraically increasing bargain rapidities and volumes.<ref name="Preis">See for example Preis, Mantegna, 2003.</ref>&nbsp; The "fat tails" are also observed in [[commodity market]]s.

Presently, one of the main results of econophysics comprises the explanation of the [[Fat-tailed distribution|"fat tails"]] in the distribution of many kinds of financial data as a [[Universality class|universal]] self-similar [[scaling invariance|scaling]] property (i.e. scale invariant over many orders of magnitude in the data),<ref>The physicists noted the scaling behaviour of "fat tails" through a letter to the scientific journal ''[[Nature (journal)|Nature]]'' by Rosario N. Mantegna and H. Eugene Stanley: ''Scaling behavior in the dynamics of an economic index'', Nature Vol. 376, pages 46-49 (1995)</ref> arising from the tendency of individual market competitors, or of aggregates of them, to exploit systematically and optimally the prevailing "microtrends" (e.g., rising or falling prices). These "fat tails" are not only mathematically important, because they comprise the  [[risk]]s, which may be on the one hand, very small such that one may tend to neglect them, but which - on the other hand - are not negligible at all, i.e. they can never be made exponentially tiny, but instead follow a measurable algebraically decreasing power law, for example with a ''failure probability'' of only <math>P\propto x^{-4}\,,</math> where ''x'' is an increasingly large variable  in the tail region of the distribution considered (i.e. a price statistics with much more than 10⁸ data). I.e., the events considered are not simply "outliers" but must really be taken into account and cannot be "insured away".<ref name="Preis" />&nbsp; It appears that it also plays a role that near a change of the tendency (e.g. from falling to rising prices) there are typical "panic reactions" of the selling or buying agents with algebraically increasing bargain rapidities and volumes.<ref name="Preis">See for example Preis, Mantegna, 2003.</ref>&nbsp; The "fat tails" are also observed in [[commodity market]]s.

 

As in quantum field theory the "fat tails" can be obtained by complicated "[[nonperturbative]]" methods, mainly by numerical ones, since they contain the deviations from the usual [[Gaussian distribution|Gaussian approximations]], e.g. the [[Black–Scholes model|Black–Scholes]] theory.  Fat tails can, however, also be due to other phenomena, such as a random number of terms in the central-limit theorem, or any number of other, non-econophysics models. Due to the difficulty in testing such models, they have received less attention in traditional economic analysis.

 

As in quantum field theory the "fat tails" can be obtained by complicated "[[nonperturbative]]" methods, mainly by numerical ones, since they contain the deviations from the usual [[Gaussian distribution|Gaussian approximations]], e.g. the [[Black–Scholes model|Black–Scholes]] theory.  Fat tails can, however, also be due to other phenomena, such as a random number of terms in the central-limit theorem, or any number of other, non-econophysics models.   Due to the difficulty in testing such models, they have received less attention in traditional economic analysis.

 

 

* [[Bose–Einstein condensation (network theory)]]

* [[Bose–Einstein condensation (network theory)]]

* [[Potential game#Bounded Rational Models|Potential Game (Bounded Rational)]]

* [[Potential game]]

* [[Complexity economics]]

* [[Complexity economics]]

{{Reflist|30em}}

{{Reflist|30em}}

Category:Applied and interdisciplinary physics

Category:Applied and interdisciplinary physics

类别: 应用和跨学科物理学

类别: 应用和跨学科物理学

 

Category:Mathematical finance

Category:Mathematical finance

类别: 数学金融

类别: 数学金融

Category:Schools of economic thought

Category:Schools of economic thought

类别: 经济思想流派

类别: 经济思想流派

[[Category:Statistical mechanics]]

* [[Rosario N. Mantegna]], [[H. Eugene Stanley]], ''An Introduction to Econophysics: Correlations and Complexity in Finance'', [http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=0521620082 Cambridge University Press (Cambridge, UK, 1999)]

Category:Statistical mechanics

Category:Statistical mechanics

类别: 统计力学

类别: 统计力学

[[Category:Interdisciplinary subfields of economics]]

*Sitabhra Sinha, Arnab Chatterjee, Anirban Chakraborti, [[Bikas K Chakrabarti]]. ''Econophysics: An Introduction'', [http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527408150,descCd-authorInfo.html  Wiley-VCH (2010)]

Category:Interdisciplinary subfields of economics

Category:Interdisciplinary subfields of economics