山区高速公路选线设计的探讨

对在公路建设中如何贯彻可持续发展战略进行了简要论述,阐明了作者的观点;介绍山区公路的特点,对山区公路传统的选线原则提出了不同的看法;结合常德至吉首高速公路湘西段,从整体把握路线方案,平、纵指标分析,局部方案比选等方面谈山区公路选线。     

风险投资家的最优激励契约模型研究--一种基于逆向选择和道德风险条件下的博弈模型分析

为减少风险投资融资中风险投资家的逆向选择和道德风险,风险投资者必须设立一套有效的激励机制来让风险投资家选择,从而根据风险投资家选择的结果来甄别其真实能力类型,同时又能激励其努力工作。文章建立了风险投资家能力类型和努力都是不可观测条件下的最优激励契约模型,并根据显示原理,利用最优控制理论求出了最优解进而进行了分析。得出的结论是:最优激励契约能使高能力风险投资家乐于选择具有高强度激励、低固定收入和风险小的项目,同时又能激励其签约后更加努力工作。     

“Itô's Lemma” and the Bellman Equation for Poisson Processes: An Applied View

Using the Hamilton-Jacobi-Bellman equation, we derive both a Keynes-Ramsey rule and a closed form solution for an optimal consumption-investment problem with labor income. The utility function is unbounded and uncertainty stems from a Poisson process. Our results can be derived because of the proofs presented in the accompanying paper by Sennewald (2006). Additional examples are given which highlight the correct use of the Hamilton-Jacobi-Bellman equation and the change-of-variables formula (sometimes referred to as ``Itô's Lemma'') under Poisson uncertainty.     

Integrating ecosystem services into conservation assessments: A review

A call has been made for conservation planners to include ecosystem services into their assessments of conservation priority areas. The need to develop an integrated approach to meeting different conservation objectives and a shift in focus towards human wellbeing are some of the motivations behind this call. There is currently no widely accepted approach to planning for ecosystem services. This study contributes towards the development of this approach through a review of conservation assessments and the extent to which they include ecosystem services. Of the 476 conservation assessments identified by a set of search terms on the Web of Science, 100 were randomly selected for this review. Of these only seven had included ecosystem services, while another 13 had referred to ecosystem services as a rationale for conservation without including them in the assessment. The majority of assessments were based on biodiversity pattern data while 19 used data on ecological processes. A total of 11 of these 19 assessments used processes, which could be linked to services. Ecosystem services have witnessed an increase in attention received in conservation assessments since the year 2000, however trends were not apparent beyond this date. In order to assess which types of ecosystem services and how they have been accounted for in conservation assessments, we extended our review to include an additional nine conservation assessments which included ecosystem services. The majority included cultural ecosystem services, followed by regulatory, provisioning and supporting services respectively. We conclude with an analysis of the constraints and opportunities for the integration of ecosystem services into conservation assessments and highlight the urgent need for an appropriate framework for planning for ecosystem services.     

The politics of redistributive social insurance

This paper analyses the political support for a social insurance that includes elements of redistribution when there exists an imperfect private insurance alternative. Individuals differ both in their income and risk. The social insurance is compulsory and charges an income-related contribution with pooling of risks. The private insurance is voluntary and charges a contribution based on individual risks. However due to the adverse selection problem, private insurance companies provide only partial insurance. Adopting a non-expected utility model, we show that there is a general majority support for social insurance and that this support is increasing with risk aversion. We also show that a mixed insurance is politically impossible, regardless of the degree of redistribution of social insurance and the joint distribution of risk and income in the population. Lastly, we analyse how the political support for social insurance is affected by any change in its redistributive component and the possibility of using genetic tests.     

Selection dynamics and adaptive behavior without much information

This paper uses the experimental method to investigate behavior in a coordination game when the information available to subjects is limited to their feasible choices and their experienced payoffs. In the experiment subjects converge to an absorbing state at rates that are orders of magnitude faster than reinforcement learning algorithms, but slower than under complete information. This state is very close to a mutual best response outcome. All cohorts converged to the market statistic predicted by the interior equilibrium regardless of the information conditions or the stability conditions. Eric Battalio programmed the graphical user interface. The National Science Foundation and Texas Advanced Research Program provided financial support. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation or the Texas Advanced Research Program.     

基于生命周期的虚拟企业知识活动分析及其伙伴选择过程研究

随着新经济的到来,知识越来越成为企业快速响应市场机遇和获取竞争优势的最短缺资源.而企业自身知识资源的有限性使企业越来越多地采用虚拟企业的高级形态--知识联盟型虚拟企业来弥补企业知识资源的不足以快速响应变化的市场需求.本文首先对知识联盟型虚拟企业的知识缺口类型进行研究和划分,然后分析并描述虚拟企业生命周期各阶段的知识活动;在此基础之上,探讨虚拟企业组建阶段考虑知识要素的伙伴选择过程;最后,针对不同的知识缺口,提出伙伴选择过程的评价指标体系设计中应考虑的知识性因素.     

Art as an investment: Short and long-term comovements in major painting markets

This paper examines the short and long-term price linkages among major art and equity markets over the period 1976–2001. The art markets examined are Contemporary Masters, French Impressionists, Modern European, 19^th Century European, Old Masters, Surrealists, 20^th Century English and Modern US paintings. A global equity index (with dividends and capitalisation changes) is also included. Multivariate cointegration procedures, Granger non-causality tests, level VAR and generalised variance decomposition analyses based on error-correction and vector autoregressive models are conducted to analyse short and long-run relationships among these markets. The results indicate that there is a stationary long-run relationship and significant short and long run causal linkages between the various painting markets and between the equity market and painting markets. However, in terms of the percentage of variance explained most painting markets are relatively isolated, and other painting markets are generally more important than the equity market in explaining the variance that is not caused by innovations in the market itself. This suggests that opportunities for portfolio diversification in art works alone and in conjunction with equity markets exist, though in common with the literature in this area the study finds that the returns on paintings are much lower and the risks much higher than in conventional financial markets.The authors would like to thank delegates to the 14th Australasian Finance and Banking Conference, University of New South Wales, seminar participants at the Queensland University of Technology and Massey University, Masaki Katsuura, and two anonymous referees for helpful comments on earlier versions of this paper. The financial assistance of a Queensland University of Technology, Faculty of Business Research Initiative Grant is also gratefully acknowledged.     

How to invest over the life cycle: Insights from theory

We analyse the state of the art in the field of life cycle portfolio choice, a recent strand of the literature on intertemporal portfolio selection. Life cycle models are designed to identify optimal savings and portfolio policies over the lifetime of investors. They can help to improve pension schemes by showing how these could be specifically tailored to the individual employee’s circumstances to overcome the ‘one-size-fits-all’ philosophy still prevailing in parts of the mandatory retirement savings system. To facilitate comparison, we first describe set-up, solution method and characteristic results for a basic model and then derive a general framework to classify existing contributions. We highlight the models’ strengths and weaknesses and assess their ability to resolve existing portfolio puzzles. Lessons from the literature are summarized and promising areas for further research identified. JEL classifications G11, D14, D91, H55     

遗传模拟退火算法在配送中心选址中的应用

物流配送中心是现代物流系统的枢纽,而配送中心地址的确定是物流系统分析的核心内容.合理的配送中心选址可以降低企业的运营成本,本文根据配送中心地址问题的特点和要求,提出用遗传模拟退火算法解决选址模型.最后通过一个实例求得了模型的最优解,验证了该算法的有效性.