Why evolution does not always lead to an optimal signaling system

This paper gives a complete characterization of neutrally stable strategies for sender–receiver games in the style of Lewis, or Nowak and Krakauer [Lewis, D., 1969. Convention: A Philosophical Study. Harvard Univ. Press, Cambridge, MA; Nowak, M., Krakauer, D., 1999. The evolution of language. Proc. Nat. Acad. Sci. USA 96, 8028–8033]. Due to the dynamic implications of neutral stability, the replicator dynamics of this model does not necessarily lead to the rise of an optimal signaling system, where every state of the world is bijectively linked to one signal and vice versa, but it can be trapped in suboptimum situations where two (or more) signals are used for the same event, or two (or more) events are associated with one and the same signal.     

商业聚集效应的动力学分析

商业聚集促进了区域商业经济的持续增长,提升了商业企业的经济效益。聚集到底给企业带来了多大的经济效应?企业之间应该如何协调发展?通过非线性动力学建模、分析,解决了这两个实际问题,为商业企业决策提供理论参考。     

医疗服务费对公立医院公益性影响的系统动力学分析

医疗服务费是医务人员技术劳动价值的体现,调整医疗服务费是当前医疗改革的焦点。本文应用系统动力学方法通过分析医疗服务费调整通过提升医师技术价值从而对医务人员诊疗行为和患者就医行为以及医药企业营销行为的影响,构建医疗服务费对医改影响的因果关系图,分析了医疗服务费调整的关键作用,即促使医方合理用药,提高诊疗质量;促使患者就诊分流,满意度提高;促使医药企业以药品质量赢得市场。最后本文根据研究结论提出相关建议:坚定医疗服务费改革的信心,并及时采取保障措施,一是医院管理制度上保障医务人员价值实现,二是加强基层医疗资源配置吸纳患者的分流。     

Interest Rates and Credit Risk

This paper explores the effects of shifts in interest rates on corporate leverage and default in the context of a dynamic model in which the link between leverage and default risk comes from the lower incentives of overindebted entrepreneurs to guarantee firm survival. The need to finance new investment pushes firms' leverage ratio above some state‐contingent target toward which firms gradually adjust through earnings retention. The response to interest rate rises and cuts is both asymmetric and heterogeneously distributed across firms. Our results help rationalize some of the evidence regarding the risk‐taking channel of monetary policy.     

Are Small Firms Really Less Productive?

Small and medium-sized establishments (SMEs) account for a large proportion of industrial employment and production in almost all countries. Moreover, the recent literature emphasizes the role SMEs play in nurturing entrepreneurship and generating new products and processes. Although SMEs could be a source of new ideas and innovations, there are substantial productivity differences between small and large establishments. In this paper, we analyze three sources of productivity differentials: technical efficiency, returns to scale, and technical change. Our analysis on the creation, survival, and growth of new establishments in Turkish manufacturing industries in the period 1987–1997 shows that all these three factors play a very important role in determining the survival probability and growth prospects of new establishments.     

Specialization dynamics

This paper proposes a new empirical framework for analyzing specialization dynamics. A country’s pattern of specialization is viewed as a distribution across sectors, and statistical techniques for analyzing the evolution of this entire distribution are employed. The empirical framework is implemented using data on 20 industries in seven OECD countries since 1970. We find substantial mobility in patterns of specialization. Over time horizons of 5 years, this is largely explained by forces common across countries, including world prices and common changes in technical efficiency. Over longer time horizons, country-specific changes in factor endowments become more important. There is no evidence of an increase in countries’ overall degree of specialization.     

Employment effects of business dynamics: Mice, Gazelles and Elephants

Much of the theoretical work on industry dynamics focuses on the role of ‘noisy’ selection and incomplete information on firm entry and survival. We extend this research by looking at the impact of firm heterogeneity on employment effects for 320 U.S. Metropolitan Statistical Areas (MSA). We find that only start-ups with greater than 20 and less than 500 employees have persistent employment effects over time and only in large diversified metropolitan regions. Therefore, both the type of entry (Gazelles) and the characteristics of the region are important for employment growth.

Multiple Levels of Corporate Sustainability

According to Dr. Clare Graves, mankind has developed eight core value systems,1 as responses to prevailing circumstances. Given different contexts and value systems, a one-solution-fits-all concept of corporate sustainability is not reasonable. Therefore, this paper presents various definitions and forms of sustainability, each linked to specific (societal) circumstances and related value systems. A sustainability matrix– an essential element of the overall European Corporate Sustainability Framework – is described showing six types of organizations at different developmental stages, with different forms of corporate sustainability, each supported by specific institutional arrangements.     

Changing Sources of Household Income,Poverty, and Sectoral Inequality in Sri Lanka, 1990–2006

Comparing dynamic changes in household income and poverty among urban, rural, and estate sectors in Sri Lanka from 1990 to 2006, this study finds that a shift of household income away from farm to nonfarm sources is accompanied by a significant improvement in household income and reduction in poverty, particularly in the rural sector. Major contributing factors are the rise in returns to labor, in general, and educated labor, in particular, due to the development of the nonfarm labor market. Persistently low income among estate households can be explained primarily by the limited availability of nonfarm employment opportunities and the low education levels of working members.     

Informal Credit,Usury, or Support? A Case Study for Vietnam

The informal credit market remains an important source of finance for the poor in Vietnam. Yet, little if anything is known about the impact of informal loans on poverty and inequality, and the Vietnamese government has no policies towards the informal credit market. In the present study paper, we found that the effect of credit from friends and relatives on per capita expenditure is positive but not statistically significant. Meanwhile, the effect of credit from private moneylenders on per capita expenditure is positive and statistically significant. Borrowing from private moneylenders increases per capita expenditure of households by around 15%. Further, it reduced the poverty incidence of borrowers by around 8.5 percentage points in 2006 and significantly decreases the poverty gap index and the poverty‐severity index. Borrowing from private moneylenders also reduces expenditure inequality, albeit at a very small magnitude.