湖南怀化市河西新区市场群落发展研究

通过对湖南怀化市河西新区市场群落发展现状的调查考察,揭示了市场群落形成的动力机制,包括体制环境与路径依赖机制、区位优势与区域功能导向机制、政府扶持与政策优惠的加速机制、民营资本争利于市的驱动机制、外来经商人员和知名厂商的激活机制、产销一体化互动机制。针对区域整体规划滞后、市场重复建设、划行归市不甚理想、市场开发的房地产化趋势、投资环境欠佳等主要问题,提出了改善投资环境和经营环境、形成各部门协同发展合力,吸引经营大户和知名厂商进驻市场、培植市场主体商户,关注市场新变化、拓展新业态、发掘新空间,加强产销衔接、推进工贸一体化,强化市场人才培育等对策建议。     

Theory and practice of monetary policy

Summary. We consider an optimally managed renewable resource with stochastic non-concave growth function. We characterize the conditions under which the optimal policy leads to global extinction, global conservation and the existence of a safe standard of conservation. Our conditions are specified in terms of the economic and ecological primitives of the model: the biological growth function, the welfare function, the distribution of shocks and the discount rate. Our results indicate that, unlike deterministic models, extinction and conservation in stochastic models are not determined by a simple comparison of the growth rate and the discount rate; the welfare function plays an important role.Received: 20 October 2004, Revised: 28 February 2005, JEL Classification Numbers: D90, O11, O41, Q32.Santanu Roy: Correspondence toResearch on this paper was completed when the second author visited Cornell University in July, 2003. We thank the Center for Analytic Economics and the Department of Economics at Cornell University for making this research visit possible. The current version has gained considerably from the comments made by an anonymous referee.     

Dynamic causality between the U.S. stock market,the Chinese stock market and the global gold market: implications for individual investors’ diversification strategies

This paper proposes a generalization of the prior VAR and EGARCH model to explore the linkage between returns and volatility transmissions in the U.S. stock market, the Chinese stock market, and the global gold market from 10 July 1996 to 20 July 2018. We found that past returns of the U.S. stock market can predict the current returns of the other two markets, and that significant reciprocal volatility transmission existed within and across all three markets. We further implemented average out-of-sample (OOS) forecasting to show that a risk-adjusted portfolio, such as mean-variance with sample estimator, does not outperform an equal-weighted portfolio. This provides insights for individual investors and helps to explain the ongoing disagreement in the portfolio literature concerning the effectiveness of risk-adjusted portfolios and equal-weighted portfolios when the number of assets is small.     

基于产品生命周期的物流系统动态规划研究

由于在产品不同生命周期阶段市场竞争具有不同的特征,因此企业采取的市场战略也有较大的差别。应用物流系统的动态评价方法,研究了有效支撑企业产品市场竞争战略的物流系统应该具有的关键性特征,并在此基础上分析了如何组织企业内外部的物流资源,使得物流系统成本最小化的动态规划问题。     

Optimal Intervention Policies for a Small Monetary Economy

We analyze the gains from trade for a small cash-in-advance economy with endogenous labor supply and learning-by-doing in the accumulation of human capital. Contrary to previous findings, we show that free trade is not optimal independently of the relative amount of cash required for the purchase of each good. Furthermore, a monetary rule à la Friedman can eliminate distortions deriving from the cash-in-advance constraint only under segmented financial markets; in any case, it cannot restore the economic optimum. Finally, we identify government intervention policies, such as wage and export subsidies, that can be welfare improving.     

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.     

湖南城市竞争力的动态比较

文章首先阐述了城市竞争力动态比较的研究意义和具体途径,然后选取了适当的指标体系和分析年代,并建立了动态比较的计量数学模型,运用因子分析法对湖南省14个城市竞争力进行了动态的测算和分析。分析结果表明:湖南城市竞争力呈现出明显的非均衡发展特点;各城市在近5年内竞争力增长的趋势和幅度均有所不同;湖南城市竞争力水平与其增长能力具有显著的正相关性。     

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     

The Optimal Timing of Adoption of a Green Technology

We study the optimal timing of adoption of a cleaner technology and its effects on the rate of growth of an economy in the context of an AK endogenous growth model. We show that the results depend upon the behavior of the marginal utility of environmental quality with respect to consumption. When it is increasing, we derive the capital level at the optimal timing of adoption. We show that this capital threshold is independent of the initial conditions on the stock of capital, implying that capital-poor countries tend to take longer to adopt. Also, country-specific characteristics, as the existence of high barriers to adoption, may lead to different capital thresholds for different countries. If the marginal utility of environmental quality decreases with consumption, a country should never delay adoption; the optimal policy is either to adopt immediately or, if adoption costs are “too high”, to never adopt. The policy implications of these results are discussed in the context of the international debate surrounding the environmental political agenda.      

基于GIS的露天煤矿区土地动态变化分析

本文选用1985年和2005年两期土地利用现状图,借助MAPGIS软件,采用单一土地利用动态度和综合土地利用动态度等指数模型,分析了安太堡露天煤矿1985～2005年土地利用类型的数量变化和空间变化特征。结果表明:(1)各类土地利用类型综合动态度为2.07%;(;2)安太堡露天煤矿20年来各类土地利用类型的增减在空间上存在快速的变化,通过统计分析显示,灌木林地、工业用地、裸土地增加迅速,而旱地、未成林地大幅度减少;(3)安太堡露天煤矿空间动态演变特点为空间扰动剧烈、地类变化明显、空间变化持续时间长。