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。     

Incentive Regulation of Prices When Costs are Sunk

We present a model featuring irreversible investment, economies of scale, uncertain future demand and capital prices, and a regulator who sets the firm’s output price according to the cost structure of a hypothetical replacement firm. We show that a replacement firm has a fundamental cost advantage over the regulated firm: it can better exploit the economies of scale because it has not had to confront the historical uncertainties faced by the regulated firm. We show that setting prices so low that a replacement firm is just willing to participate is insufficient to allow the regulated firm to expect to break even whenever it has to invest. Thus, unless the regulator is willing to incur costly monitoring to ensure the firm invests, revenue must be allowed in excess of that required for a replacement firm to participate. This contrasts with much of the existing literature, which argues that the market value of a regulated firm should equal the cost of replacing its existing assets. We also obtain a closed-form solution for the regulated firm’s output price when this price is set at discrete intervals. In contrast to rate of return regulation, we find that resetting the regulated price more frequently can increase the risk faced by the firm’s owners, and that this is reflected in a higher output price and a higher weighted-average cost of capital.     

南京市人地关系合理性研究

随着我国城市化进程的加速，中心城市将会得到快速发展，大量的人口将会在中心城聚集，会使中心城市的人地矛盾变得越来越复杂。文章以南京市为例，对其进行分析研究和客观评价，确定城市用地与人口的合理关系，并提出相应的实施对策。     

浅议我国最佳外汇储备规模

截止到2005年12月底，我国的外汇储备已达到8000亿美元，关于其数额是多是少的争论进行得如火如荼。本文对充足外汇储备给我国经济和社会带来的有利之处进行了理论上的分析后．又采取数学方法对我国2004年最佳的外汇储备数额进行了测算．得出了一个结论：我国的外汇储备并不多。然后，在此基础上对我国外汇储备的管理提出了几点建议。     

物流企业实现规模效益的途径探讨

针对当前物流企业规模较小、效益较差的现状，本文提出通过扩大企业规模的措施，以实现规模经济，提高企业效益。     

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     

Some properties of the length of the shortest half

This paper discusses some properties of the length of the shortest half proposed by Rousseeuw and Leroy (1988) as a robust scale estimator.     

Distinguishing external from internal scale effects: The case of public infrastructure

The recent applied production theory literature focusing on the economic performance of firms has increasingly recognized the importance of scale effects on costs and therefore efficiency. These scale effects may include short run returns due to fixity of privately demanded inputs (i.e., capital, long run internal returns to scale, and external factors affecting costs. Since these different types of scale effects can be thought of as shifts in and movements along cost curves, the different cost effects of such factors can be identified in a framework which explicitly takes them into account in the definition ofscale.In this article we formalize such a framework, and then use it to measure short run, long run (internal) and external scale effects from fixity of private capital, nonconstant returns to scale and public infrastructure. We then use these measures to identify the impacts of these different scale factors on productivity growth. The focus on public infrastructure as an important external scale factor is motivated by the current theoretical and policy interest in this issue; we show how a structural production theory model provides a rich basis for the analysis of the cost effects of infrastructure investment.     

政府公共投资的经济效应分析

关于政府公共投资的经济效应,学术界有颇多争论,虽然一系列研究成果发现公共资本与经济增长正相关,但也有一些学者通过研究得出了截然相反的结论。文章运用经济增长理论分析政府公共投资的经济效应,并以中国相关数据为样本进行实证检验,实证检验得出结果:公共投资与产出正相关。在此基础上,文章根据我国目前所处的经济发展阶段,运用计量经济模型,估计出我国当前政府公共投资的最优规模,即公共投资占GDP的合理比重为4.5%,公共投资占财政总支出的合理比重为22%左右。     

湖南工业化进程的生态环境压力趋势分析

随着人类经济活动，尤其是工业的加速发展，资源能源的利用和环境污染对生态环境这一人类赖以生存和发展的基础产生了越来越大的压力。基于湖南经济发展中工业化进程的加快对生态环境的压力加大这一状况，现利用生态环境压力指数法（ESl）对生态环境所造成的压力作趋势分析。结果表明，湖南自1999年至今，随着大力推进工业化进程，资源能源压力及环境污染压力均明显加大。故走生态工业化道路、建设节约型社会是唯一出路。