Mortality,Human Capital and Persistent Inequality

Available evidence suggests high intergenerational correlation of economic status and persistent disparities in health status between the rich and the poor. This paper proposes a mechanism linking the two. We introduce health capital into a two-period overlapping generations model. Private health investment improves the probability of surviving from the first period of life to the next and, along with education, enhances an individual’s labor productivity. Poorer parents are of poor health, unable to invest much in reducing mortality risk and improving their human capital. Consequently, they leave less for their progeny. Despite convex preferences and technologies, initial differences in economic and health status may perpetuate across generations when annuities markets are imperfect.Additional support was provided by the National Science Foundation. Additional support was provided by the National Science Foundation.     

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.     

城市住宅用地空间扩张机制与调控对策

城市住宅用地空间扩张的必然性与土地资源的稀缺性这一对矛盾,在城市化进程迅速推进的今天显得尤为尖锐,如何实现城市居民居住质量的提高与城市土地资源的可持续利用成为迫切需要解决的问题。文章总结了我国当前城市住宅用地扩张的特点,从经济、制度、技术以及人为干预四个方面对我国当前城市住宅用地空间扩张机制进行了解析,并对城市住宅用地空间扩张过程所出现的问题提出了相关调控措施。     

中国居民物质性消费与收入关系及其空间特征

对1993年起中国开始步入过剩经济时代进行了实证分析，给出了沿海与内地城镇及农村居民物质性消费与收入的恩格尔函数及其特征；在收入－消费关系空间特征分析的基础上，指出居民消费倾向内地高于沿海，内地城镇高于农村。最后从居民物质性消费与收入关系及空间特征角度讨论了现阶段加速中西部地区发展的必要性与合理性。     

城乡居民收入差距的动态演变:1988～2002年

中国城乡居民收入差距已经引起广泛关注。文章以住户调查数据为基础,利用泰尔指数分解、G.Fields分解、Blinder分解、分位回归分解等多种方法讨论了1988年、1995年和2002年“城乡”因素本身对城乡居民收入差距的贡献。这些分解结果表明我国的城乡差距较显著并在不断扩大;而且城乡差距更不利于农村中的低收入人群。     

Free Entry under Uncertainty

When focusing on firm’s risk-aversion in industry equilibrium, the number of firms may be either larger or smaller when comparing market equilibrium with and without price uncertainty. In this paper, we introduce risk-averse firms under cost uncertainty in a model of spatial differentiation and show that the impact of uncertainty will increase the number of firms in an industry. With increased uncertainty, the risk premium of the marginal buyer increases by more than the risk premium of the average buyer, so that the price increases by more than the risk premium. When turning to the free entry game, we find that the market generates too many firms.     

泰山旅游需求时空分布规律及旅游者行为特征的初步研究

泰山旅游需求存在着明显的时空分布规律．调查显示．游人数量的日变化、周变化和年内变化十分显著；客源地主要分布于山东及其周边省市；旅游区内部以泰山中路和岱顶的需求强度最大。最后对旅游交通方式、旅游消费、旅客职业构成双重游率等旅游者行为特征进行了分析。     

Coping with Technological Change: The Role of Ability in Making Inequality so Persistent

This study provides an explanation to the evolution of wage inequality over the last 30 years and supports this explanation with evidence. A faster rate of technological progress introduces new unknown elements at the workplace. The need to cope with the unknown accentuates the role of ability and thus increases wage inequality within and between education groups. Inasmuch as education is an irreversible investment project the rise in within group inequality BOOSTS UP the rise of between group inequality. Guided by this theory we turn to the PSID for evidence. Using parents' education to approximate child's ability we show the following set of results: (a) Controlling for education of the child, parents' education contributed much more in the 1980s to his wage growth than in the 1970s. (b) The correlation between the parents' and the child's education increases from the 1970s to the 1980s. (c) The return to college education for an individual with no ability rents did not change—it remains steady at the 23 percent. (d) Facts (a)–(c) CANNOT be attributed to the impact of parent's income. It is parents' education and not parents' income that is more relevant for son's economic outcomes in the 1980s.     

旅游地阻力面理论初探--五大连池风景名胜区为例

以生态学中的阻力面理论为依托，创建了符合旅游规划需要的旅游地阻力面理论模型，构建了旅游景点、景区、旅游地、旅游区域之间联系的阻力层次体系，建立了旅游空间联系关系的影响因子系统，提出了旅游地阻力面理论在指导区域、地方及旅游区规划中的作用，并以国家级风景名胜区五大连池为例展示了旅游地阻力面理论在地方旅游开发建设实践中的现实作用。     

基于顾客需求的物流地产价值创新

借助对物流地产与商业地产、工业地产的比较分析,探讨了物流地产的内涵,对普洛斯的物流地产运作模式进行了案例分析,并对其物流地产的价值创新战略进行了阐释。