The Middle Class Consensus and Economic Development

A middle class consensus is defined as a high share of income for the middle class and a low degree of ethnic divisons. The paper links a middle class consensus to resource endowments, along the lines of the provocative thesis of Engerman and Sokoloff (1997 and 2000). This paper exploits this association using tropical resource endowments as instruments for inequality. A higher share of income for the middle class and lower ethnic divisions are associated with higher income and higher growth, as well as with more education, better health, better infrastructure, better economic policies, less political instability, less civil war and ethnic minorities at risk, more social modernization and more democracy.     

The nature of the steady state in models of optimal growth under uncertainty

Summary. We study a one-sector stochastic optimal growth model with a representative agent. Utility is logarithmic and the production function is of the Cobb-Douglas form with capital exponent . Production is affected by a multiplicative shock taking one of two values with positive probabilities p and 1-p. It is well known that for this economy, optimal paths converge to a unique steady state, which is an invariant distribution. We are concerned with properties of this distribution. By using the theory of Iterated Function Systems, we are able to characterize such a distribution in terms of singularity versus absolute continuity as parameters and p change. We establish mutual singularity of the invariant distributions as p varies between 0 and 1 whenever . More delicate is the case . Singularity with respect to Lebesgue measure also appears for values such that . For and Peres and Solomyak (1998) have shown that the distribution is a.e. absolutely continuous. Characterization of the invariant distribution in the remaining cases is still an open question. The entire analysis is summarized through a bifurcation diagram, drawn in terms of pairs .Received: 9 April 2002, Revised: 29 October 2002, JEL Classification Numbers: C61, O41.Correspondence to: Tapan MitraThis research was partially supported by CNR (Italy) under the "Short-term mobility" program and by M.U.R.S.T. (Italy) National Group on "Nonlinear Dynamics and Stochastic Models in Economics and Finance" . We are indebted to Rabi Bhattacharya for providing us with the reference to Solomyak's (1995) paper. The present version has benefitted from comments by Mukul Majumdar and two anonymous referees.     

Evaluating Projects and Assessing Sustainable Development in Imperfect Economies

We are interested in three related questions:(1) How should accounting prices be estimated?(2) How should we evaluate policy change in animperfect economy? (3) How can we check whetherintergenerational well-being will be sustainedalong a projected economic programme? We do notpresume that the economy is convex, nor do weassume that the government optimizes on behalfof its citizens. We show that the same set ofaccounting prices should be used both forpolicy evaluation and for assessing whether ornot intergenerational welfare along a giveneconomic path will be sustained. We also showthat a comprehensive measure of wealth,computed in terms of the accounting prices, canbe used as an index for problems (2) and (3)above. The remainder of the paper is concernedwith rules for estimating the accounting pricesof several specific environmental naturalresources, transacted in a few well knowneconomic institutions.     

科研开发与经济增长——兼论科研开发的溢出效应

经济划分为科研部门和非科研部门，科研开发对经济增长的作用及科研对非科研部门具有外溢效应。1999-2003年30个省市自治区的面板数据表明，科研开发对经济增长具有较大的拉动作用，同时科研开发部门对其他部门的外溢作用明显为正。     

非国有经济发展对中国经济增长质量影响机理研究——来自VEC模型的新证据

转轨以来,中国非国有经济的发展促进了经济增长的数量扩张.这是因为,经济非国有化改革作为一种制度创新,是一种增量式改革.这种改革使得体制内利益在未受影响的条件下,实现了帕雷托式的增长.然而,非国有经济的发展并没有带来中国经济增长质量的同比改善.这是因为,中国民营企业发展一般都过分强调以利润为中心,忽略环境成本,并且由于融资困难等因素导致了其技术创新能力的弱化;其次,中国引进的外资不仅在技术和管理创新的扩散效应上没能达到预期效果,而且日益增加的加工贸易通过转移定价方式使中国经济不能充分享有出口增长带来的利润贡献.     

河北省农村经济增长的消费因素影响及对策研究

当社会经济发展的主要矛盾从供给约束向需求约束转变，经济增长的主要支撑因素从供给扩张向需求拉动转变时，扩大需求成为必要。农村居民的消费水平是影响农村经济增长的重要因素，本文在介绍河北省农村居民的消费现状基础上，分析制约农村居民消费水平的因素，追而提出发展河北省农村消费市场，促进农村经济增长的对策。     

The Productivity of US States since 1880

This study uses state-level variation in labor productivity levels at twenty-year intervals between 1880 and 1980 to examine the relative importance of institutional and geographical influences in explaining observed and persistent differences in standards of living over time and across regions. Focusing on fundamental rather than proximate influences, we find that both institutional characteristics and some physical geography characteristics account for a high proportion of the differences in state productivity levels: states with navigable waterways, a large minerals endowment, and no slaves in 1860, on average, had higher labor productivity levels throughout the sample period. However, we find little support for two other influences that have previously received attention—climate and latitude.     

Quantitative growth effects of subsidies in a search theoretic R&D model

Should government subsidize R&D and does it matter how these subsidies are allocated? We examine these questions in a dynamic model where R&D is described as sequential sampling from a distribution of new ideas. Successful discoveries affect future available resources and incentives for further R&D. Consequently, there may be under-investment in R&D. We study the effect of government interventions aimed at fostering growth through R&D. Calibrating the model with aggregate data from the Israeli business sector allows us to quantitatively compare two forms of support resembling those actually used to encourage R&D in the Israeli business sector: (i) an unrestricted subsidy that may be used at the recipients' discretion to finance R&D or other investments, (ii) a subsidy earmarked by the government for R&D activities only. While there is no theoretical way to determine which of the two subsidies will have a greater impact on search for new ideas and growth, we find that in the calibrated economy both subsidies have a significant but similar impact on the economy's output and TFP growth rates. Accordingly, in the case of the Israeli business sector, the incentives to conduct R&D were sufficiently strong, and no R&D-specific encouragement was needed. However, a sensitivity analysis reveals that for economies characterized by other parameter values this result may not be true. Correspondence to: B. Bental     

R＆D、R＆D溢出、内生增长和内生收敛

根据强调知识与技术创新、知识与技术溢出重要性的当代内生增长理论，本文建立了一个将R＆D和R＆D溢出与资本积累之间、R＆D和R＆D溢出与总产出增长之间直接关联起来的动态模型。面板数据协整检验实证分析结果表明R＆D和R＆D溢出与资本积累之间、R＆D和R＆D溢出与总产出增长之间分别存在显著的正面长期协整关联。进一步的分析表明，R＆D与资本积累之间、R＆D与总产出增长之间分别存在显著的长期双向格兰杰因果关系。由此观知，R＆D乃长期经济增长源泉之所在。另一方面，尽管资本积累或总产出增长并不格兰杰导致R＆D溢出，证据表明R＆D溢出格兰杰导致资本积累和总产出增长。这种由R＆D溢出到资本积累和总产出增长的单向格兰杰因果关系意味着尽管知识与技术的跨国传播并非必然发生。其实为世界经济增长的重要动力。     

Study on the planning principles of urban forest

The urban forest is the main body for the urban forestry management. There are not unified rules and standards for the planning of the urban forest yet in China. This paper discusses the planning principles of the urban forest： the priority of the ecological function, the adaptation to local condilions, the optimization in the whole system, the mutual dependence of forest and city, the culturecontinuance and recreation satisfaction, sustainable development and operability, etc. This paper takes Changsha as an example to elaborate the planning principles of the urban forest. Firstly, Changsba urban forest ecosphere is composed of the eco-garden, the round-the-city forest belt, the ecological isolation belt, the green channel, the landscape of the rivers and streams, the forest park, the biodiversity reserve and the eco-forest in suburb area. It aims to make every kind of ecological essential factors organically merge into the complex city ecosystem to build an eco-city, to strengthen the connection of wide-open space with various habitats spots, to promote resident＇s accessibility, to perfect landscape ecology, and to make full use of the ecological function of urban forest. When we construct the urban forest, we must optimize the comprehensive benefit and make the urban forest structure and the layout in the best condition in order to buiM the harmonious green city for both man and nature to realize the whole optimization of the city system by the complex functions of the urban forest in ecology, environmental protection, landscape, recreation, etc.