Modeling defaults of companies in multi-stage supply chain networks

The interest in supply chain networks and their analysis as complex systems is rapidly growing. The physical approach to the topic draws on the concept of heterogenous interacting agents. The interaction among agents is considered as a repeated process of orders and production. The dynamics of production in the supply chain network which we observe is nonlinear due to the random failures in processes of orders and production. We introduce an agent-based model of a supply chain network which represents in more detail the real economic environment in which firms operate. We focus on the influence of local processes on the global economic behavior of the system and study how the proposed modifications change the general properties of the model. We observe collective bankruptcies of firms, which lead to self-emerging network structures. Our results give insight into the dynamics of default processes in supply chain networks, which have important implications both for risk managers and policy makers. Based on the simulations we show that agent-based modeling is a powerful tool for optimization of supply chain networks.     

养老基金投资的谨慎人规则及其在我国社保基金投资管理中的适用

与数量限制模式相比,谨慎人规则的监管模式有利于养老金管理机构根据基金的状况和市场状况确定基金投资政策,提高基金资产分散风险和获取更高投资收益的能力。目前,我国在全国社保基金投资运作中逐步引入谨慎人规则的时机业已成熟,相关法律应逐步放宽对社保基金的投资品种的限制,拓宽投资渠道,主要发挥理事会在社保基金投资运作和风险控制中的核心作用,由理事会根据证券市场的情况独立决定社保基金的投资政策,并通过委托投资合同和委托投资方针,对社保基金投资管理人的投资品种及各品种的比例进行约束。     

Declining Discount Rates: The Long and the Short of it

The last few years have witnessed important advances in our understanding of time preference and social discounting. In particular, several rationales for the use of time-varying social discount rates have emerged. These rationales range from the ad hoc to the formal, with some founded solely in economic theory while others reflect principles of intergenerational equity. While these advances are to be applauded, the practitioner is left with a confusing array of rationales and the sense that almost any discount rate can be justified. This paper draws together these different strands and provides a critical review of past and present contributions to this literature. In addition to this we highlight some of the problems with employing DDRs in the decision-making process, the most pressing of which may be time inconsistency. We clarify their practical implications, and potential pitfalls, of the more credible rationales and argue that some approaches popular in environmental economics literature are ill-conceived. Finally, we illustrate the impact of different approaches by examining global warming and nuclear power investment. This includes an application and extension of Newell and Pizer [‘Discounting the benefits of climate change mitigation : how much do uncertain rates increase valuations?’ Journal of Environmental Economics and Management 46 (2003) 52] to UK interest rate data.     

The Economics and Bioeconomics of Folk and Scientific Classification

Synopsis This paper is the product of a collaboration between a biologist (Ghiselin 1997) who works on the philosophy of classification and an economist (Landa 1981, 1994) who works on the ‘Economics of Identity’: how and why people classify people based on identity in the context of a theory of ethnic trading networks. In developing the ‘bioeconomics’ (the synthesis of economics with biology) of classification, we crossed a number of disciplinary boundaries—anthropology, economics, sociology, biology, and cognitive psychology including evolutionary psychology’s ‘fast and frugal’ heuristics. Using a bioeconomics approach, we argue that folk classifications—the classifications used by ordinary persons—have much in common with scientific classifications: underlying both is the need for economy of information processing in the brain, for the efficient organization of knowledge, and for efficiency of information acquisition and transmission of information to others. Both evolve as a result of trial and error, but in science there is relatively more foresight, understanding, and planning.     

Tax Interaction Effects,Environmental Regulation,and “Rule of Thumb” Adjustments to Social Cost

Preexisting distortions in factor markets complicate the estimation of the social welfare effects of regulatory interventions. The existence of these tax interaction effects (TIEs) suggests that general equilibrium (GE) approaches should be used to evaluate regulatory policies. However, formal GE analysis is not always feasible for the numerous environmental regulations proposed by federal, state, and local agencies. The question addressed in this paper is whether an empirically based rule of thumb upward adjustment factor is appropriate to properly scale social cost estimates in environmental policy. We argue that such rule of thumb adjustments are significantly less reliable than estimates based on a detailed general equilibrium analysis because of the uncertainty about both the magnitude and sign of the social cost distortion. In addition to addressing this question, the paper gives an overview of TIEs and their relevance to environmental policy.     

Hayek Reads the Literature on the Emergence of Norms

Hayek’s approach to cultural and institutional evolution has been frequently criticized because it is explicitly based on the controversial notion of (cultural) group selection. In this paper this criticism is rejected on the basis of recent works on biological and cultural evolution. The paper’s main contention is that Hayek employed group selection as a tool for the explanation of selection among several equilibria, and not as a vehicle for the emergence of out of equilibrium behavior (i.e., altruism). The paper shows that Hayek’s ideas foreshadowed some of the most promising developments in the current literature on the emergence of norms. JEL Classification: B31, B41     

欠发达农区产业集群的网络组织结构及其区域效应分析

基于河南农区三个不同网络类型集群129家企业的调查,运用社会网络分析法,通过对比三个集群中的衍生网络、情感网络、咨询网络以及合作网络的网络特性,鉴别出欠发达农区集群网络中的核心节点、重要关系及不同网络组织类型的区域效应.研究发现:先导企业是集群衍生的孵化器,亲属或厂属关系是区域产业繁衍的关键渠道;大企业是技术创新和扩散的中心,供需关系和技术工人流动是区域学习的重要路径;中等企业是情谊联系的活跃点,长期合作关系能培养区域信任;中介组织与服务机构、"生产组织者"是企业间合作的"桥梁",上下游的经济联系对区域合作影响巨大.从集群的网络组织类型来看,混合性的转包网络和互补性的垂直网络比竞争性的水平网络对区域内的网络学习、信任培养、合作行动以及区域发展能带来更好的效果.     

专利技术垄断、仿冒进入与政府管制政策

文章通过构建政府、正版厂商与仿冒厂商三者之间的Stackelberg博弈模型,并考虑仿冒品厂商的市场结构特征和性质,探讨了仿冒厂商进入条件下正版厂商的竞争行为、策略以及社会福利水平的变化.经研究发现:(1)市场中有仿冒厂商进入且政府稽查力度较弱的情况下,正版厂商总会选择大于独占均衡时的产出数量作为竞争的最优策略,并且,正版品的市场均衡价格要低于正版品独占时的市场均衡价格;(2)仿冒品和正版品之间具有相互替代性,但替代程度不同,仿冒品对正版品仅能部分替代,正版品对仿冒品产生完全替代作用;(3)仿冒品的存在有可能对正版厂商的利益产生正面的影响和作用;(4)在没有考虑政府管制成本的情况下,政府采取对仿冒品不予追究,或者采取严格的查处力度都会提高社会的福利水平.     

辽宁省社会保障水平的国内比较

社会保障水平是反映一个国家或地区经济发展和人们生活水平的一个重要指标,根据辽宁省近五年来社会保障支出的数据,分析计算辽宁省社会保障水平,并与国内若干省市的社会保障水平进行了比较,进而分析辽宁省的社会保障发展状况,以及与其他省市社会保障水平比较中反映出的若干问题,从而对辽宁省的社会保障水平做出总体性评价。     

社保基金股票投资组合的行业偏好初探

全国社会保障基金是价值型投资者,行业配置对其具有重要意义。通过考察2008年末全国社会保障基金的股票委托投资组合在行业配置上总体的分布情况,分析出该基金的受托人在股票市场处于周期性底部区域时偏好投资于周期型行业,尤其是传播与文化产业,交通运输与仓储业,电力、煤气及水的生产和供应业,以及房地产业,并得出了在这一时段受托人的行业配置风格与该基金的投资原则和该基金作为价值型机构投资者的定位相符的结论。