Probability of survival in a random exchange economy with dependent agents

Summary. In this paper I analyze the general equilibrium in a random Walrasian economy. Dependence among agents is introduced in the form of dependency neighborhoods. Under the uncertainty, an agent may fail to survive due to a meager endowment in a particular state (direct effect), as well as due to unfavorable equilibrium price system at which the value of the endowment falls short of the minimum needed for survival (indirect terms-of-trade effect). To illustrate the main result I compute the stochastic limit of equilibrium price and probability of survival of an agent in a large Cobb-Douglas economy. Received June 7, 2001; revised version: January 7, 2002 RID="*" ID="*" I would like to thank Mukul Majumdar and Thomas DiCiccio for helpful discussion and an anonymous referee for valuable comments and suggestions.     

Land conservation and tenure security in Kenya: Boserup's hypothesis revisited

Land conservation technologies used by farmers are known to play an important role in improving farm incomes and household welfare in the long run. For this reason substantial investments have been made in research to improve agricultural technologies in various parts of the world, from the development of new crop varieties to new practices of land management. This paper explores the impact of land rights among other factors on adoption of soil and water conservation practices. The study further tests for Boserup's hypothesis (correlation between population density, land conservation and property rights) using panel survey data collected from farming households. The key findings of the paper are that property right regimes and population density affect both the decision to conserve land as well as the type of conservation practices used by farmers. The results further suggest a positive correlation between land tenure security and population density, thus supporting Boserup's hypothesis. The findings call for pursuit of both short-term and long-term policy measures that offer incentives for land conservation through government initiatives and participation of local communities.     

Transport development and the evolution of economic geography

In this paper, based on the recent advances in the new economic geography (e.g., Fujita et al. [12]), we analyze impacts of transport costs on the spatial patterns of economic agglomeration. We first identify prototypes from the existing models, and explain the mechanism of how transport costs influence the balance between economic forces of agglomeration and dispersion. We then investigate the transformation of the agglomeration/dispersion patterns given gradually decreasing transport costs for different goods.Received: Received: July 2004 / Accepted: January 2005, Accepted: Received: July 2004 / Accepted: January 2005, JEL Classification: R12Tomoya Mori: Correspondence toThe authors are grateful to David Bernstein, Tatsuo Hatta, Komei Sasaki, Tony E. Smith, and two anonymous referees for their valuable comments. This research is partly supported by The Grant in Aid for Research 08403001 of Ministry of Education, Science and Culture in Japan, the Murata Science Foundation, and WESCO Civil Engineering Technology Foundation.     

集聚效应对跨国公司在华区位选择的影响

本文以跨国公司区位选择微观理论为基础,利用条件Logit模型,对2007年《财富》世界500强中,1995年到2007年期间,457家美国子公司和537家欧洲子公司在华个体区位选择决定因素进行了实证分析。分析结果表明,集聚效应是样本公司区位选择的重要决定因素,在华投资的欧美制造业公司普遍采用"集聚"这一战略,其子公司大量集聚在东部地区,盲目吸收外资来缩小东—西部经济发展不平衡的政策并不合适,尤其是中部地区。因此,在文章末,本文对中国政府应该如何减小区域经济发展不平衡和合理引用外资提出了建议。     

安徽在长三角城市群中定位与空间发展战略的思考

安徽作为长三角的纵深腹地,在地理上与苏浙沪发达地区无缝对接,在资源开发、产业发展、市场开拓等方面具有广泛的合作空间,在长三角城市群经济社会发展中将发挥着重要作用.安徽省委、省政府审时度势,进一步明确了安徽加快发展的主攻方向,作出了推进东向发展,加速回归长三角的重大决策.论文在长三角城市群发展趋势分析的基础上,提出安徽省分层次、分时序融入长三角的模式,探讨了"东向发展"的安徽省域城镇发展总体战略,并对其在长三角城市群中的定位和空间发展战略做了一些思考.     

Volatility in the knowledge economy

Summary. We seek to explain the economic volatility of the last 6 years, in particular the rapid expansion and contraction of the knowledge sectors. Our hypothesis is that these sectors amplify the business cycle due to their increasing returns to scale, growing faster than others in an upswing and contracting faster in a downswing. To test this hypothesis we postulate a general equilibrium model with two sectors: one with increasing returns that are external to the firm and endogenously determined - the knowledge sector - and the other with constant returns to scale. We introduce a new measure of volatility of output, a real beta, and derive a resolving equation, from which we prove that the increasing return sectors exhibit more volatility then other sectors. We validate the main results on US macro economic data of real GDP by industry (2-3 digits SIC codes) of the 1977-2001 period, and provide policy conclusions.Received: 18 March 2002, Revised: 16 February 2004, JEL Classification Numbers: D5, D58, E10, L50, L52, O38, O51.Correspondence to: Graciela Chichilnisky     

关于提高高等数学教学质量的几个途径

随着高校的不断扩招,一般院校（特别是边远地区院校）的生源质量在逐年下降.如何提高高等数学教学质量,这是我们每一个高校数学教育工作者面临的新问题.注重初、高等数学知识与方法的衔接,实施分级教学,消除非智力因素对学习高等数学的影响是提高高等数学教学质量的几个有效途径.     

Agglomeration in an innovative and differentiated industry with heterogeneous knowledge spillovers

This paper introduces an agent-based simulation model to study the technological development, the economic performance of firms and the evolution of agglomerations in a differentiated industry. The analysis is based on the interaction and behavior of firms, which might share knowledge but at the same time are competitors on the goods markets. Firms do not only compete with quantities they can also introduce process and product innovations. The level of knowledge of a firm describes the capabilities to perform innovations. Knowledge can be accumulated by investing in R&D and by knowledge spillover, which depend on geographical and technological proximity. Simulation runs show that there is an incentive to agglomerate in young industries and that geographical proximity enhances innovation, especially the number of product innovations.      

从人口规模看我国的就业问题

我国是世界上人口最多的国家,也是世界上劳动力资源最丰富的发展中国家,其就业压力也最大。近年来,失业问题已经引起了我国各级政府和社会各界的广泛关注。从人口规模角度探讨我国的就业问题,分析人口规模对就业的影响,这对实现我国经济发展战略,实现人口与经济、社会的协调发展都具有重要意义。     

On a clear day you might see an environmental Kuznets curve

We shed some new light on the Environmental Kuznets curve (EKC) and show how it can be viewed as a particular form of equilibrium relationship, where technology and preference parameters determine the shape of the curve. In contrast to most of the literature on the EKC, we estimate a theoretically consistent model on long-run data (Swedish sulfur emission, covering the period 1900–2002). Furthermore, we test and date structural change. The model suggests four regimes, 1900–1918, 1919–1933, 1934–1967 and 1968–2002, generating four rather different patterns for pollution over time. The policy-conclusions are consonant with Pearce’s general view about the EKC: there is no theoretical presumption that it has an inverted U shape, nor should any country try to “grow out of the environmental problems” without analyzing the benefits and costs of so doing.