Incorporating Delphi results in system dynamics models: A case of Indian tea industry

The results of a Delphi study on the future of the Indian tea industry are presented. Most of the information obtained for the study helps in formulating and validating a system dynamics model. The model also considers the occurrence of new events as visualized by the panelists. It is shown, however, that the policies recommended by the panelists yield poor industry behavior when Delphi-predicted new events operate in the environment. This may be due to lack of comprehension of the complexity of interaction between policies proposed and new events visualized by the panelists. On the basis of this investigation, it is proposed that Delphi and system dynamics studies should complement each other in arriving at viable policy decisions.     

The econometric challenge to system dynamics and vice versa: Some future perspectives

In the last years, there have been some attempts to compare different approaches for dynamic modeling of socioeconomic systems and to suggest guidelines for choosing among them. This paper continues these efforts with special emphasis on system dynamics and econometrics, which are commonly regarded as the roughest competitors in this field of simulation. It will present a detailed catalogue of model features, relevant for an adequate characterization of system dynamics and econometrics, and will stress the importance to notice the interconnections that exist between different features. The paper then gives a systematic survey of the conceivable relations between system dynamics and econometrics, and closes with a short epistemological outlook.     

The World Market for Labor and the World Market for Industrial Sites

At the center of the on-going debate about the U.S. Social Security system is the question of whether the way the system is financed can cope with the future challenges posed by the retiring Baby Boom generation. The "reformers" suggest changing the design of the system by moving to fully funded defined contribution retirement plans. Others argue that the so-called demographic problems are being used as an excuse to privatize the system. But both sides spend almost all of their energy and time figuring out the timing of insolvency of the system and the validity of the assumptions made in each forecast. In contrast, the present study closely examines the changing macroeconomic dynamics of the system since the 1960s. The analysis shows that undermining of the system is caused not by demographic changes or financing mechanisms but by low wages and medical inflation.     

The Dynamics Of Localized Technological Changes. The Interaction Between Factor Costs Inducement,Demand Pull And Schumpeterian Rivalry 1

Localized technological change is the endogenous outcome of the interplay between substitution costs. Switching costs and learning processes. New technologies are introduced when market pressures induce firms to change the levels of their inputs and their techniques. The dynamics ol localized technological change is the result us the interaction between three processes: it) the Schumpcterian competition process as analyzed by the replicator dynamics and failure inducement mechanisms. b) factor substitution stemming from changes in factors markets. and c) post-Keynesian demand pull pressures resulting from productivity growth. In such conditions out-of-equilibrium exchanges and localized technological changes drive a recursive process that is path-dependent in two senses, first it is highly sensitive to the initial conditions of the system. and second it is shaped by the interactions of agents.     

Sunspot fluctuations in dynamics with predetermined variables

Summary. In this paper, I study the existence of Sunspot Equilibria in a general framework whose dynamics allow for the presence of predetermined variables in the system. The main motivation for this research comes from the fact that previous studies did not allow for such predetermined variables which, nevertheless, appear quite naturally in economic models. I show, for a non-negligible subset of dynamics with predetermined variables verifying usual assumptions, the existence of Stationary Sunspot Equilibria fluctuating between an arbitrary finite number of states arbitrarily close to a steady state. Received: March 1, 1995; revised version September 18, 1996     

干旱区土地利用结构调整的SD模型研究：以新疆吐鲁番市为例

土地利用结构的调整是我国目前土地利用总体规划的两大核心内容之一。我国干旱地区生态环境十分脆弱、稳定性差。土地沙漠化、盐碱化、草场退化等现象十分严重，本文以新疆吐鲁番市为例．分析了该市土地利用现状和存在的问题．运用系统动力学模型．建立了土地利用结构调整的动态模型，充当地制订中长期土地利用总体规划提供科学依据。     

农业系统资源配置非线性系统模型分析

农业生产是自然再生产和经济再生产的有机结合的过程,农业系统高度耦合了自然生态系统、社会经济系统等复杂大系统,具有非线性和耗散性等特性。本文应用系统分析的原理和方法,从农业系统的演化运行角度,建立以市场价格和政府控制为基础的农业系统资源配置的非线性系统动力学模型,并指出资源配置应该从系统演化的角度进行考虑,这有助于资源流向合理有效配置的方向。最后以江苏为例分析验证。     

Changes in Occupational Earnings along the U.S.-Mexico Border between 1900 and 1920

In a 2006 paper, Professor Gregory Hayden argued that system dynamics is an inadequate tool for explaining the institutional systems principles of hierarchy, feedback and openness. The purpose of this paper is to show that many of Professor Hayden's claims are either misguided or incorrect. The paper also reinforces the argument that system dynamics modeling can add significant value to traditional institutional economic analysis.     

On Clustering in the Location of R&D: Statics and Dynamics

Empirical analyses of research and development find strong evidence that these activities tend to cluster geographically. Clusters are thought to emerge from the presence of localized positive externalities. This paper presents a model of this clustering behaviour. We find that phase changes in clustering exist both as the strength of local externalities changes and as the degree of heterogeneity among firms changes. The dynamics of the system are examined as it responds to shocks to the size of the market for R&D output, and the length scale of the spatially dependent externalities. Dynamic responses take place in two distinct stages: a rapid response to the change in market systems which takes place throughout the space, with litlle regard to externality effects; followed by a slow re-agglomeration process as producers change their spatial decisions to lower the costs of the new production level.     

Coupled economic-ecological systems with slow and fast dynamics — Modelling and analysis method

The purpose of this article is to contribute to the exploration of non-convex dynamics in coupled human-nature systems. We study welfare issues associated with the management of a human-nature complex adaptive system with a threshold and a stochastic driver. We exemplify with a specific system where we link changes in the number and diversity of birds to the abundance of a pest (insects) that causes damages to goods and services valuable to human beings. We present a method that simplifies the analysis and helps us discuss different management models that combine direct and indirect controls of the pest. This allows us to show that 1) the choice of control method depends in a highly non-linear way on biodiversity characteristics and 2) the socially optimal outcome may not be reachable using price instruments. Hence the price vs. quantity debate needs to be revisited using a complex adaptive system lens.     

Education for the masses? The interaction between wealth,educational and political inequalities

This paper presents a simple model of distribution dynamics, in which the distributions of wealth, education and political power are circularly endogenous. Different levels of education translate into different income and wealth levels. Political power may (or may not) vary with wealth, and in turn affects decisions on the level of public expenditure on education. Since the market for education credit is imperfect, some people might need to rely on public schooling, the quality of which depends on those expenditure levels. As a result, educational opportunities differ along the wealth distribution. The dynamic system displays multiple equilibria, some of which are characterized by a vicious circle of interaction between educational, wealth and political inequalities. These particular equilibria, which are more unequal, are also shown to be inefficient in terms of aggregate output levels. Switching equilibria may be achieved through redistribution of political power.
JEL classification: D31, D63.     

基于系统动力学的中国通货膨胀形成机制研究

运用系统动力学方法和理论对我国通货膨胀的形成机制进行分析,提出通货膨胀系统是由经济发展子系统、存贷款子系统、财政收支子系统、国际收支子系统构成的复杂多重反馈系统,运用系统动力学Vensim软件,建立了通货膨胀系统的因果反馈模型,揭示了通货膨胀系统形成机制的主导因素,进而建立通货膨胀系统的结构流图和方程,对通货膨胀系统动态定量分析,通过调整相关参数进行仿真和预测,并在此基础上提出相关政策建议。     

The geometry of inductive reasoning in games

Summary.  This paper contributes to the recent focus on dynamics in noncooperative games when players use inductive learning. The most well-known inductive learning rule, Brown’s fictitious play, is known to converge for games, yet many examples exist where fictitious play reasoning fails to converge to a Nash equilibrium. Building on ideas from chaotic dynamics, this paper develops a geometric conceptualization of instability in games, allowing for a reinterpretation of existing results and suggesting avenues for new results. Received: October 27, 1995 revised version May 2, 1996     

区域配电网全寿命周期成本优化研究

为了有效控制配电网运营成本和提高效益,针对新一轮电力体制改革的深入改革,区域配电网全寿命周期成本优化已成为一个重要研究方向。本文首先借助系统动力学模型分析了配电网复杂成本构成和筛选了影响成本的关键因子,并采用了改进蒙特卡法对关键影响因子进行混合抽样,得出配电网各关键因子对区域配电网全寿命周期成本影响的综合灵敏度系数;其次,建立了以关键影响因子对配电网全寿命周期成本总影响量最小为目标的成本优化模型,以及提出了GAACS组合算法对模型进行求解;最后,选取了某省的10kV配电网区域进行了实例分析,结果可得,经济条件对配电网成本影响最大,以及技术条件差的区域降低成本能力较大。。     

城市联盟动力系统研究

城市联盟打破行政区域划分的限制,消除城市市场壁垒;促进城市一体化建设,优化资源配置。研究了城市联盟的动力系统,揭示了城市联盟的根本动力是城市间利益趋同;驱动力是经济一体化进程的加快;连同产业动力、市场动力、技术动力、学习动力、资本动力、结构动力、资源动力、制度动力共同构成城市联盟的动力系统。通过对城市联盟的弓弦箭模型进行分析得出利益趋同性越好,越易达到共振,城市联盟获得的增值价值越大,城市联盟走得越远。     

On the Dynamic Foundation of Evolutionary Stability in Continuous Models

We show in this paper that none of the existing static evolutionary stability concepts (ESS, CSS, uninvadability, NIS) is sufficient to guarantee dynamic stability in the weak topology with respect to standard evolutionary dynamics if the strategy space is continuous. We propose a new concept, evolutionary robustness, which is stronger than the previous concepts. Evolutionary robustness ensures dynamic stability for replicator dynamics in doubly symmetric games. Journal of Economic Literature Classification Numbers: C70, 72.     

基于系统动力学的高技术集群产学研集成创新研究

基于3个维度的邻近度——地理邻近度、知识邻近度、组织邻近度,从系统动力学视角提出了高技术集群产学研集成创新的基本分析框架,建立了高技术集群产学研集成创新的系统动力学模型,并应用Vensim PLE软件对模型进行了仿真模拟。结果表明,在提高知识邻近度或组织邻近度时,高技术集群产学研创新能力确有一定程度的提高,但若能使得两种邻近度同时得到提高,集群的产学研创新能力将会得到大幅提升。     

基于系统动力学模型的铁路建设项目宏观经济效益评价

系统动力学采用系统仿真方法进行长期动态模拟,不受描述方程的高阶非线性限制,也不受数据不完全的影响,且处理问题直观形象,便于人机对话。本文将系统动力学与区域经济-交通系统相结合,建立了铁路建设项目宏观经济效益评价的系统动力学模型,并对模型进行了合理性检验,证明了系统动力学方法在铁路建设项目宏观经济效益评价中具有可操作性和推广价值。