Usually financial crises go along with bubbles in asset prices, such as the housing bubble in the US in 2007. This paper attempts to build a mathematical model of financial bubbles from an econophysics, and thus a new...Usually financial crises go along with bubbles in asset prices, such as the housing bubble in the US in 2007. This paper attempts to build a mathematical model of financial bubbles from an econophysics, and thus a new perspective. I find that agents identify bubbles only with a time delay. Furthermore, I demonstrate that the detection of bubbles is different on either the individual or collective point of view. Second, I utilize the findings for a new definition of asset bubbles in finance. Finally, I extend the model to the study of asset price dynamics with news. In conclusion, the model provides unique insights into the properties and developments of financial bubbles.展开更多
We present a review of our recent research in econophysics, and focus on the comparative study of Chinese and western financial markets. By virtue of concepts and methods in statistical physics, we investigate the tim...We present a review of our recent research in econophysics, and focus on the comparative study of Chinese and western financial markets. By virtue of concepts and methods in statistical physics, we investigate the time correlations and spatial structure of financial markets based on empirical high-frequency data. We discover that the Chinese stock market shares common basic properties with the western stock markets, such as the fat-tail probability distribution of price returns, the long-range auto-correlation of volatifities, and the persistence probability of volatilities, while it exhibits very different higher-order time correlations of price returns and volatilities, spatial correlations of individual stock prices, and large-fluctuation dynamic behaviors. Furthermore, multi-agent-based models are developed to simulate the microscopic interaction and dynamic evolution of the stock markets.展开更多
The article considers the econophysical analysis of the relationship between monopoly and competition by using the methods, terms of physics. And it was investigated the philosophy of progress. It has been shown that ...The article considers the econophysical analysis of the relationship between monopoly and competition by using the methods, terms of physics. And it was investigated the philosophy of progress. It has been shown that in the transition from absolute monopoly to imperfect monopoly, the system becomes more complex, and its output characteristics depend on time, because monopoly is a natural, competitive is derivative process. Competition is created as a result of the interaction of at least two ~monopoly firms＂ through the ~market field＂ that they create to increase the production which is necessary of non-linear products over time. To do this, it is sufficient to have a multitude of firms interacting with each other under the influence force of ~market field＂. To create the necessary conditions, it is sufficient to have a high level of university education and a legal field for competition and unbreakable antitrust legislation. By acquiring technology and creating conditions for competition in the market, it is possible to achieve progress even without having a strong science. The term ~progress＂ has received a new content and is defined as the value of a numerically equal increase in the rate of production per unit time or production per squared time. It has been shown that the relationship between monopoly and competition is very simple and there is no contradiction between them. Initially, the market is born as a monopoly, and then analogical firms were created, competition between firms begins展开更多
Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual a...Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like ＂intelligence＂ remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents＇ intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.展开更多
Emergence refers to the existence or formation of collective behaviors in complex systems.Here,we develop a theoretical framework based on the eigen microstate theory to analyze the emerging phenomena and dynamic evol...Emergence refers to the existence or formation of collective behaviors in complex systems.Here,we develop a theoretical framework based on the eigen microstate theory to analyze the emerging phenomena and dynamic evolution of complex system.In this framework,the statistical ensemble composed of M microstates of a complex system with N agents is defined by the normalized N×M matrix A,whose columns represent microstates and order of row is consist with the time.The ensemble matrix A can be decomposed as■,where r=min(N,M),eigenvalueσIbehaves as the probability amplitude of the eigen microstate U_I so that■and U_I evolves following V_I.In a disorder complex system,there is no dominant eigenvalue and eigen microstate.When a probability amplitudeσIbecomes finite in the thermodynamic limit,there is a condensation of the eigen microstate UIin analogy to the Bose–Einstein condensation of Bose gases.This indicates the emergence of U_I and a phase transition in complex system.Our framework has been applied successfully to equilibrium threedimensional Ising model,climate system and stock markets.We anticipate that our eigen microstate method can be used to study non-equilibrium complex systems with unknown orderparameters,such as phase transitions of collective motion and tipping points in climate systems and ecosystems.展开更多
We propose an empirical behavioral order-driven(EBOD)model with price limit rules,which consists of an order placement process and an order cancellation process.All the ingredients of the model are determined based on...We propose an empirical behavioral order-driven(EBOD)model with price limit rules,which consists of an order placement process and an order cancellation process.All the ingredients of the model are determined based on the empirical microscopic regularities in the order flows of stocks traded on the Shenzhen Stock Exchange.The model can reproduce the main stylized facts in real markets.Computational experiments unveil that asymmetric setting of price limits will cause the stock price to diverge exponentially when the up price limit is higher than the down price limit and to vanish vice versa.We also find that asymmetric price limits have little influence on the correlation structure of the return series and the volatility series,but cause remarkable changes in the average returns and the tail exponents of returns.Our EBOD model provides a suitable computational experiment platform for academics,market participants,and policy makers.展开更多
Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic di...Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic discounting, a q-exponential discounting model based on Tsallis’ statistics. In order to experimentally examine the mathematical characteristics of the q-exponential social discounting models for gain and loss in humans, we estimated the parameters of the q-exponential social discounting models by assessing the points of subjective equality (indifference points) at seven social distances. We observed that gain was more steeply social-discounted than loss. Usefulness of the q-exponential social discounting model in social physics, econophysics, and cultural neuroeconomics are discussed.展开更多
Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been propose...Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been proposed in econophysics (Takahashi, 2007, Physica A). We examined (a) fitness of the models to behavioral data of probability discounting of both gain and loss;and (b) relationships between parameters in the q-exponential probability discounting model across gain and loss. Our results demonstrated that, for both gain and loss, the q-exponential model better fits the behavioral data than exponential and hyperbolic functions, and there is the sign effect in q-exponential probability discounting. Relationships between Kahneman-Tversky’s prospect theory in behavioral economics and the q-exponential probability discounting are high-lightened.展开更多
The article presents results of reflections on practical applications of econophysical models in different fields and areas of the management support and answers the question： In what areas and scopes of the manageme...The article presents results of reflections on practical applications of econophysical models in different fields and areas of the management support and answers the question： In what areas and scopes of the management process is usage of econophysical models already effective or very likely to be effective？ It discusses the problem of gravity models and minority games used in economic and social sciences. Their applications in areas such as trade, transport, analysis of financial market fluctuations, or decision making are presented. An attempt is made to identify missing pieces in the area of broadly understood management, and possible directions for further research are suggested. The paper uses research methods such as desk research and literature review.展开更多
Using an analogy between finance and astrophysics,this study aims to investigate whether there exists a mechanism that can describe the explosive increase in the number of traded cryptocurrencies and the cryptocurrenc...Using an analogy between finance and astrophysics,this study aims to investigate whether there exists a mechanism that can describe the explosive increase in the number of traded cryptocurrencies and the cryptocurrency market in general.In physics,the Schwarzschild radius indicates that black holes are constantly expanding because of their mass increase.Enriching this analogy,we consider the cryptocurrency market as a self-gravitational body whose mass is denoted by(1)the number of traded cryptocurrencies and(2)in terms of increasing market capitalization for a given number of traded cryptocurrencies.By analyzing weekly snapshot data of all traded cryptocurrencies from January 4,2009,to June 14,2020,we find evidence that the above-mentioned mechanism exists.The results clearly indicate the self-gravitational property of the cryptocurrency market,which is direct evidence toward the hypothesis that the changes in the traded cryptocurrencies are a positive function of the previous period’s number of traded cryptocurrencies.展开更多
Whether people tend to punish criminals in a socially-optimal manner (i.e., hyperbolic punishment) or not is unknown. By adopting mathematical models of probabilistic punishment behavior (i.e., exponential, hyperbolic...Whether people tend to punish criminals in a socially-optimal manner (i.e., hyperbolic punishment) or not is unknown. By adopting mathematical models of probabilistic punishment behavior (i.e., exponential, hyperbolic, and q-exponential probability discounting model based on Tsallis thermodynamics and neuroeconomics, Takahashi, 2007, Physica A;Takahashi et al., 2012, Applied Mathematics), we examined 1) fitness of the models to behavioral data of uncertain punishment, and 2) deviation from the socially optimal hyperbolic punishment function. Our results demonstrated that, the q-exponential punishment function best fits the behavioral data, and people overweigh the severity of punishment at small punishing probabilities and underweigh the severity of punishment at large punishing probabilities. In other words, people tend to punish crimes too severely and mildly with high and low arrest rate (e.g., homicide vs. excess of speed limit), respectively. Implications for neuroeconomics and neurolaw of crime and punishment (Takahashi, 2012, NeuroEndocrinology Letters) are discussed.展开更多
Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We ...Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We have proposed that psychophysical time commonly explains anomalies in both decisions (Takahashi, 2011, Physica A;Takahashi et al., 2012, J Behav Econ & Finance). By adopting the q-exponential time and probability discounting models, our psychophysical and behavioral economic experiment confirmed that nonlinear distortion of psychophysical time is a common cause of the anomalies in decision both over time and under risk (i.e., intertemporal choice and decision under risk). Implications for psychophysical neuroeconomics and econophysics are discussed.展开更多
This study attempts to investigate the relationship between monopoly and competition and the philosophy of progress,using the methods,models,and terms from physics.The term“progress”is a newly adopted term and is de...This study attempts to investigate the relationship between monopoly and competition and the philosophy of progress,using the methods,models,and terms from physics.The term“progress”is a newly adopted term and is defined as the value of an increase in the production rate per unit of time.It is shown that to achieve progress,it is necessary to increase the production on a non-linear basis over time.Therefore,it is enough to have many firms that interact with each other under the influence of“market forces”.It is important to have a high level of university education,a legal environment for competition and indestructible antitrust laws.Even without strong science,you can make progress by acquiring technology and creating conditions for competition in the market.A factor that strongly influences progress,of course,is technology.For the development of technology,there is a great need for science.Science is a very powerful factor that affects the non-linear change in the economic development.It is shown that during the transition period from an absolute monopoly to an imperfect monopoly the system becomes more complex,and its output characteristics become non-linear as a function of time.It was found that the relationship between monopoly and competition is very simple,and there is no contradiction between them.Initially,the market is born as a monopoly,and then with the creation of similar firms,competition,as the natural market process,begins between them.展开更多
The present paper is an attempt to bridge the gulf between economics and econophysics. That is, constructing a chaos-based theoretical model, we show the behavior of the goal-driven agents exhibits the behavior of the...The present paper is an attempt to bridge the gulf between economics and econophysics. That is, constructing a chaos-based theoretical model, we show the behavior of the goal-driven agents exhibits the behavior of the purpose-free agents. Main conclusion is: economy becomes chaos if 1) capital gain of the middle class people is large enough for them to consume eight times as much as their income gain and 2) market for the middle class people is large enough and number of the middle class people is 16 times as large as the amount of products made by one producer.展开更多
In mathematical physics and psychology, “quantum decision theory” has been proposed to explain anomalies in human decision-making. One of such quantum models has been proposed to explain time inconsistency in human ...In mathematical physics and psychology, “quantum decision theory” has been proposed to explain anomalies in human decision-making. One of such quantum models has been proposed to explain time inconsistency in human decision over time. In this study, we conducted a behavioral experiment to examine which quantum decision models best account for human intertemporal choice. We observed that a q-exponential model developed in Tsallis’ thermodynamics (based on Takahashi’s (2005) nonlinear time perception theory) best fit human behavioral data for both gain and loss, among other quantum decision models.展开更多
Intermittent or multifractal behavior has been reported in various markets,and the impact of the COVID-19 pandemic has been investigated.However,the impact of the COVID-19 pandemic on global spot markets for staple fo...Intermittent or multifractal behavior has been reported in various markets,and the impact of the COVID-19 pandemic has been investigated.However,the impact of the COVID-19 pandemic on global spot markets for staple foods has not yet been studied.We fill this gap by investigating the grain and oilseeds index(GOI)and its five sub-indices,wheat,maize,soybean,rice,and barley,released by the International Grains Council(IGC).We perform statistical tests on the presence of intrinsic multifractal behavior in subsamples before and during the COVID-19 pandemic using five multifractal analysis approaches.The results show that intrinsic multifractality is less likely in the(sub-)samples of rice and soybean,whereas the(sub-)samples of wheat and maize are more likely to possess mul-tifractal nature.Only some(sub-)samples showed that the subsamples during cOVID-19 were more intermittent than the subsamples before COVID-19.展开更多
In the past two decades, statistical physics was brought into the field of finance, applying new methods and concepts to financial time series and developing a new interdiscipline ＂econophysics＂. In this review, we ...In the past two decades, statistical physics was brought into the field of finance, applying new methods and concepts to financial time series and developing a new interdiscipline ＂econophysics＂. In this review, we introduce several commonly used methods for stock time series in econophysics including distribution functions, correlation functions, detrended fluctuation analysis method, de- trended moving average method, and multifractal analysis. Then based on these methods, we review some statistical properties of Chinese stock markets including scaling behavior, long-term correla- tions, cross-correlations, leverage effects, antileverage effects, and multifractality. Last, based on an agent-based model, we develop a new option pricing model -- financial market model that shows a good agreement with the prices using real Shanghai Index data. This review is helpful for people to understand and research statistical physics of financial markets.展开更多
Mutually interacting components form complex systems and these components usually have long- range cross-correlated outputs. Using wavelet leaders, we propose a method for characterizing the joint multifractal nature ...Mutually interacting components form complex systems and these components usually have long- range cross-correlated outputs. Using wavelet leaders, we propose a method for characterizing the joint multifractal nature of these long-range cross correlations; we call this method joint multifractal analysis based on wavelet leaders （MF-X-WL）. We test the validity of tile MF-X-WL method by performing extensive numerical experiments on dual binomial measures with multifractal cross correlations and bivariate fractional Brownian motions （bFBMs） with monofractal cross correlations. Both experiments indicate that MF-X-WL is capable of detecting cross correlations in synthetic data with acceptable estimating errors. We also apply the MF-X-WL method to pairs of series from financial markets （returns and volatilities） and online worlds （online numbers of different genders and different societies） and determine intriguing joint multifractal behavior.展开更多
Agent-based modeling is a powerful simulation technique to understand the collective behavior and microscopic interaction in complex financial systems. Recently, the concept for determining the key parameters of agent...Agent-based modeling is a powerful simulation technique to understand the collective behavior and microscopic interaction in complex financial systems. Recently, the concept for determining the key parameters of agent-based models from empirical data instead of setting them artificially was sug- gested. We first review several agent-based models and the new approaches to determine the key model parameters from historical market data. Based on tile agents＇ behaviors with heterogeneous personal preferences and interactions, these models are successful in explaining the microscopic origi- nation of the temporal and spatial correlations of financial markets. We then present a novel paradigm combining big-data analysis with agent-based modeling. Specifically, from internet query and stock market data, we extract the information driving forces and develop an agent-based model to simulate the dynamic behaviors of complex financial systems.展开更多
文摘Usually financial crises go along with bubbles in asset prices, such as the housing bubble in the US in 2007. This paper attempts to build a mathematical model of financial bubbles from an econophysics, and thus a new perspective. I find that agents identify bubbles only with a time delay. Furthermore, I demonstrate that the detection of bubbles is different on either the individual or collective point of view. Second, I utilize the findings for a new definition of asset bubbles in finance. Finally, I extend the model to the study of asset price dynamics with news. In conclusion, the model provides unique insights into the properties and developments of financial bubbles.
基金supported by the National Natural Science Foundation of China(Grant Nos.11375149,11075137,and J1210046)the Natural Science Foundationof Zhejiang Province of China(Grant No.Z6090130)
文摘We present a review of our recent research in econophysics, and focus on the comparative study of Chinese and western financial markets. By virtue of concepts and methods in statistical physics, we investigate the time correlations and spatial structure of financial markets based on empirical high-frequency data. We discover that the Chinese stock market shares common basic properties with the western stock markets, such as the fat-tail probability distribution of price returns, the long-range auto-correlation of volatifities, and the persistence probability of volatilities, while it exhibits very different higher-order time correlations of price returns and volatilities, spatial correlations of individual stock prices, and large-fluctuation dynamic behaviors. Furthermore, multi-agent-based models are developed to simulate the microscopic interaction and dynamic evolution of the stock markets.
文摘The article considers the econophysical analysis of the relationship between monopoly and competition by using the methods, terms of physics. And it was investigated the philosophy of progress. It has been shown that in the transition from absolute monopoly to imperfect monopoly, the system becomes more complex, and its output characteristics depend on time, because monopoly is a natural, competitive is derivative process. Competition is created as a result of the interaction of at least two ~monopoly firms＂ through the ~market field＂ that they create to increase the production which is necessary of non-linear products over time. To do this, it is sufficient to have a multitude of firms interacting with each other under the influence force of ~market field＂. To create the necessary conditions, it is sufficient to have a high level of university education and a legal field for competition and unbreakable antitrust legislation. By acquiring technology and creating conditions for competition in the market, it is possible to achieve progress even without having a strong science. The term ~progress＂ has received a new content and is defined as the value of a numerically equal increase in the rate of production per unit time or production per squared time. It has been shown that the relationship between monopoly and competition is very simple and there is no contradiction between them. Initially, the market is born as a monopoly, and then analogical firms were created, competition between firms begins
文摘Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like ＂intelligence＂ remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents＇ intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.
基金supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZD-SSW-SYS019)。
文摘Emergence refers to the existence or formation of collective behaviors in complex systems.Here,we develop a theoretical framework based on the eigen microstate theory to analyze the emerging phenomena and dynamic evolution of complex system.In this framework,the statistical ensemble composed of M microstates of a complex system with N agents is defined by the normalized N×M matrix A,whose columns represent microstates and order of row is consist with the time.The ensemble matrix A can be decomposed as■,where r=min(N,M),eigenvalueσIbehaves as the probability amplitude of the eigen microstate U_I so that■and U_I evolves following V_I.In a disorder complex system,there is no dominant eigenvalue and eigen microstate.When a probability amplitudeσIbecomes finite in the thermodynamic limit,there is a condensation of the eigen microstate UIin analogy to the Bose–Einstein condensation of Bose gases.This indicates the emergence of U_I and a phase transition in complex system.Our framework has been applied successfully to equilibrium threedimensional Ising model,climate system and stock markets.We anticipate that our eigen microstate method can be used to study non-equilibrium complex systems with unknown orderparameters,such as phase transitions of collective motion and tipping points in climate systems and ecosystems.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.U1811462,71671066,and 71532009)the Fundamental Research Funds for the Central Universities.
文摘We propose an empirical behavioral order-driven(EBOD)model with price limit rules,which consists of an order placement process and an order cancellation process.All the ingredients of the model are determined based on the empirical microscopic regularities in the order flows of stocks traded on the Shenzhen Stock Exchange.The model can reproduce the main stylized facts in real markets.Computational experiments unveil that asymmetric setting of price limits will cause the stock price to diverge exponentially when the up price limit is higher than the down price limit and to vanish vice versa.We also find that asymmetric price limits have little influence on the correlation structure of the return series and the volatility series,but cause remarkable changes in the average returns and the tail exponents of returns.Our EBOD model provides a suitable computational experiment platform for academics,market participants,and policy makers.
文摘Social discounting has been attracting attention in behavioral psychology, econophysics, and neuroeconomics. Several mathematical models have been proposed for social discounting;exponential discounting, hyperbolic discounting, a q-exponential discounting model based on Tsallis’ statistics. In order to experimentally examine the mathematical characteristics of the q-exponential social discounting models for gain and loss in humans, we estimated the parameters of the q-exponential social discounting models by assessing the points of subjective equality (indifference points) at seven social distances. We observed that gain was more steeply social-discounted than loss. Usefulness of the q-exponential social discounting model in social physics, econophysics, and cultural neuroeconomics are discussed.
文摘Probability discounting is defined as the devaluation of outcomes as the probability of receiving or paying those decreases. A q-exponential probability discounting model based on Tsallis’ statistics has been proposed in econophysics (Takahashi, 2007, Physica A). We examined (a) fitness of the models to behavioral data of probability discounting of both gain and loss;and (b) relationships between parameters in the q-exponential probability discounting model across gain and loss. Our results demonstrated that, for both gain and loss, the q-exponential model better fits the behavioral data than exponential and hyperbolic functions, and there is the sign effect in q-exponential probability discounting. Relationships between Kahneman-Tversky’s prospect theory in behavioral economics and the q-exponential probability discounting are high-lightened.
文摘The article presents results of reflections on practical applications of econophysical models in different fields and areas of the management support and answers the question： In what areas and scopes of the management process is usage of econophysical models already effective or very likely to be effective？ It discusses the problem of gravity models and minority games used in economic and social sciences. Their applications in areas such as trade, transport, analysis of financial market fluctuations, or decision making are presented. An attempt is made to identify missing pieces in the area of broadly understood management, and possible directions for further research are suggested. The paper uses research methods such as desk research and literature review.
基金This research is co-financed by Greece and the European Union(European Social Fund-ESF)through the Operational Programme《Human Resources Development,Education and Lifelong Learning》in the context of the project“Strengthening Human Resources Research Potential via Doctorate Research”(MIS-5000432),implemented by the State Scholarships Foundation(IKY).
文摘Using an analogy between finance and astrophysics,this study aims to investigate whether there exists a mechanism that can describe the explosive increase in the number of traded cryptocurrencies and the cryptocurrency market in general.In physics,the Schwarzschild radius indicates that black holes are constantly expanding because of their mass increase.Enriching this analogy,we consider the cryptocurrency market as a self-gravitational body whose mass is denoted by(1)the number of traded cryptocurrencies and(2)in terms of increasing market capitalization for a given number of traded cryptocurrencies.By analyzing weekly snapshot data of all traded cryptocurrencies from January 4,2009,to June 14,2020,we find evidence that the above-mentioned mechanism exists.The results clearly indicate the self-gravitational property of the cryptocurrency market,which is direct evidence toward the hypothesis that the changes in the traded cryptocurrencies are a positive function of the previous period’s number of traded cryptocurrencies.
文摘Whether people tend to punish criminals in a socially-optimal manner (i.e., hyperbolic punishment) or not is unknown. By adopting mathematical models of probabilistic punishment behavior (i.e., exponential, hyperbolic, and q-exponential probability discounting model based on Tsallis thermodynamics and neuroeconomics, Takahashi, 2007, Physica A;Takahashi et al., 2012, Applied Mathematics), we examined 1) fitness of the models to behavioral data of uncertain punishment, and 2) deviation from the socially optimal hyperbolic punishment function. Our results demonstrated that, the q-exponential punishment function best fits the behavioral data, and people overweigh the severity of punishment at small punishing probabilities and underweigh the severity of punishment at large punishing probabilities. In other words, people tend to punish crimes too severely and mildly with high and low arrest rate (e.g., homicide vs. excess of speed limit), respectively. Implications for neuroeconomics and neurolaw of crime and punishment (Takahashi, 2012, NeuroEndocrinology Letters) are discussed.
文摘Anomalies in decision over time (e.g., “hyperbolic time discounting”) and under risk (e.g., Allais paradox and hyperbolic probability discounting) have been attracting attention in behavioral and neuroeconomics. We have proposed that psychophysical time commonly explains anomalies in both decisions (Takahashi, 2011, Physica A;Takahashi et al., 2012, J Behav Econ & Finance). By adopting the q-exponential time and probability discounting models, our psychophysical and behavioral economic experiment confirmed that nonlinear distortion of psychophysical time is a common cause of the anomalies in decision both over time and under risk (i.e., intertemporal choice and decision under risk). Implications for psychophysical neuroeconomics and econophysics are discussed.
文摘This study attempts to investigate the relationship between monopoly and competition and the philosophy of progress,using the methods,models,and terms from physics.The term“progress”is a newly adopted term and is defined as the value of an increase in the production rate per unit of time.It is shown that to achieve progress,it is necessary to increase the production on a non-linear basis over time.Therefore,it is enough to have many firms that interact with each other under the influence of“market forces”.It is important to have a high level of university education,a legal environment for competition and indestructible antitrust laws.Even without strong science,you can make progress by acquiring technology and creating conditions for competition in the market.A factor that strongly influences progress,of course,is technology.For the development of technology,there is a great need for science.Science is a very powerful factor that affects the non-linear change in the economic development.It is shown that during the transition period from an absolute monopoly to an imperfect monopoly the system becomes more complex,and its output characteristics become non-linear as a function of time.It was found that the relationship between monopoly and competition is very simple,and there is no contradiction between them.Initially,the market is born as a monopoly,and then with the creation of similar firms,competition,as the natural market process,begins between them.
文摘The present paper is an attempt to bridge the gulf between economics and econophysics. That is, constructing a chaos-based theoretical model, we show the behavior of the goal-driven agents exhibits the behavior of the purpose-free agents. Main conclusion is: economy becomes chaos if 1) capital gain of the middle class people is large enough for them to consume eight times as much as their income gain and 2) market for the middle class people is large enough and number of the middle class people is 16 times as large as the amount of products made by one producer.
文摘In mathematical physics and psychology, “quantum decision theory” has been proposed to explain anomalies in human decision-making. One of such quantum models has been proposed to explain time inconsistency in human decision over time. In this study, we conducted a behavioral experiment to examine which quantum decision models best account for human intertemporal choice. We observed that a q-exponential model developed in Tsallis’ thermodynamics (based on Takahashi’s (2005) nonlinear time perception theory) best fit human behavioral data for both gain and loss, among other quantum decision models.
基金supported by the National Natural Science Foundation of China(72171083)the Fundamental Research Funds for Central Universities.
文摘Intermittent or multifractal behavior has been reported in various markets,and the impact of the COVID-19 pandemic has been investigated.However,the impact of the COVID-19 pandemic on global spot markets for staple foods has not yet been studied.We fill this gap by investigating the grain and oilseeds index(GOI)and its five sub-indices,wheat,maize,soybean,rice,and barley,released by the International Grains Council(IGC).We perform statistical tests on the presence of intrinsic multifractal behavior in subsamples before and during the COVID-19 pandemic using five multifractal analysis approaches.The results show that intrinsic multifractality is less likely in the(sub-)samples of rice and soybean,whereas the(sub-)samples of wheat and maize are more likely to possess mul-tifractal nature.Only some(sub-)samples showed that the subsamples during cOVID-19 were more intermittent than the subsamples before COVID-19.
文摘In the past two decades, statistical physics was brought into the field of finance, applying new methods and concepts to financial time series and developing a new interdiscipline ＂econophysics＂. In this review, we introduce several commonly used methods for stock time series in econophysics including distribution functions, correlation functions, detrended fluctuation analysis method, de- trended moving average method, and multifractal analysis. Then based on these methods, we review some statistical properties of Chinese stock markets including scaling behavior, long-term correla- tions, cross-correlations, leverage effects, antileverage effects, and multifractality. Last, based on an agent-based model, we develop a new option pricing model -- financial market model that shows a good agreement with the prices using real Shanghai Index data. This review is helpful for people to understand and research statistical physics of financial markets.
基金We acknowledge financial support from the National Natural Science Foundation of China （11375064 and 71532009）, the Program for Changjiang Scholars and Innovative Research Team in University （IRT1028）, and the Fundamental Re- search Funds for the Central Universities.
文摘Mutually interacting components form complex systems and these components usually have long- range cross-correlated outputs. Using wavelet leaders, we propose a method for characterizing the joint multifractal nature of these long-range cross correlations; we call this method joint multifractal analysis based on wavelet leaders （MF-X-WL）. We test the validity of tile MF-X-WL method by performing extensive numerical experiments on dual binomial measures with multifractal cross correlations and bivariate fractional Brownian motions （bFBMs） with monofractal cross correlations. Both experiments indicate that MF-X-WL is capable of detecting cross correlations in synthetic data with acceptable estimating errors. We also apply the MF-X-WL method to pairs of series from financial markets （returns and volatilities） and online worlds （online numbers of different genders and different societies） and determine intriguing joint multifractal behavior.
基金This work was supported in part by the National Natural Science Foundation of China under Grant Nos. 11375149 and 11505099
文摘Agent-based modeling is a powerful simulation technique to understand the collective behavior and microscopic interaction in complex financial systems. Recently, the concept for determining the key parameters of agent-based models from empirical data instead of setting them artificially was sug- gested. We first review several agent-based models and the new approaches to determine the key model parameters from historical market data. Based on tile agents＇ behaviors with heterogeneous personal preferences and interactions, these models are successful in explaining the microscopic origi- nation of the temporal and spatial correlations of financial markets. We then present a novel paradigm combining big-data analysis with agent-based modeling. Specifically, from internet query and stock market data, we extract the information driving forces and develop an agent-based model to simulate the dynamic behaviors of complex financial systems.
