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.     

中国石油产量的VERHULST模型的建立与分析

随着我国国民经济的快速发展,对能源的需求逐渐增大,尤其是对石油的需求逐年上升,石油的供应问题已成为普遍关注的问题。我国石油资源赋存条件差,石油增储难度大,大多数主力油田已进入中后期开采阶段,石油产量增产难度大。面对日益增加的石油需求,及时准确、科学地预测我国今后一段时期石油产量,对于制定石油需求和石油战略储备计划具有重要的现实意义。因此,根据我国石油产量变化特点,建立了Verhulst模型,经过检验,模型预测精度很高,并对2020年以前的石油产量进行了预测。     

Limit-pricing as Bertrand equilibrium

Summary. We consider a Bertrand duopoly model with increasing returns to scale where one of the firms have a cost advantage and prices vary over a grid. We find that typically more than one equilibria exist. However, there are only two perfect equilibria. Moreover, as the size of the grid becomes small, both these equilibria converge to the limit-pricing outcome. Received: February 25, 2000; revised version: January 9, 2001     

Pro-cyclical effect of sovereign rating changes on stock returns: a fact or factoid?

This article examines the effect of changes in sovereign credit ratings and their outlook on the stock market returns of European countries at different phases of business cycle. Using standard four-factor model, it records a significant average marginal effect of credit rating announcements on stock market returns. Both magnitude and significance of the effect vary with business cycle and across announcement types. However, we do not find evidence of pro-cyclical effect of sovereign rating and outlook changes on stock returns. Our results show that stock markets react more negatively to rating downgrades in recovery phases and more positively to rating upgrades in contractionary period. Both results are statistically significant and robust to various sensitivity tests.     

Economic Risk Factors and Commercial Real Estate Returns

A great deal of research has focused on the links between stock and bond market returns and macroeconomic events such as fluctuations in interest rates, inflation rates, and industrial production. Although the comovements of real estate and other asset prices suggests that these same systematic risk factors are likely to be priced in real estate markets, no study has formally addressed this issue. This study identifies the growth rate in real per capita consumption, the real T-bill rate, the term structure of interest rates, and unexpected inflation as fundamental drivers or state variables that systematically affect real estate returns. The finding of a consistently significant risk premium on consumption has important ramifications for the vast literature that has examined the (risk-adjusted) performance of real estate, for it suggests that prior findings of significant abnormal returns (either positive or negative) that have ignored consumption are potentially biased by an omitted variables problem. The results also have important implications for dynamic asset allocation strategies that involve the predictability of real estate returns using economic data.     

存在风险条件下的资本市场投资预期收益模型研究

风险是指预期收益的不确定性,是指在将来一段时间内遭受损失的可能性.进行资本市场投资,必然存在风险.资本市场投资风险就是投资预期结果(预期收益损失)的不确定性,有投资风险,就会有投资者对其进行的预期.本文建立了存在风险条件下的资本市场投资预期收益模型,并由此得出了不同投资者的预期收益--风险偏好的不同投资选择.     

油田设备润滑管理的现状与思考

分析了油田设备润滑管理现状，针对油田设备润滑管理现状及存在的问题，对油田设备润滑管理和油田企业主要设备用油进行了尝试，并对有关问题进行了较为深入的探讨，结合油田实际，认为在主要设备的润滑管理等方面还需进一步改进和提高。     

航空燃油市场的发展趋势

国际航空燃油市场虽然持续供于求，但是中国持续出现需求缺口，我们调研了中国国内航空燃油生产商和分销机构等，采用规范和实证的分析方法，提出了一些重要结论：中国航空燃油生产和供给成本高，资源配置效率有待进一步提高，航空燃油需求继续旺盛，新世纪里的十年几需求缺口可能进一步扩大。     

石油企业用户满意度测评体系的构建

用户满意度CSD(Customer Satisfaction Degree)是目前国内外质量领域和经济领域中的一项前沿研究课题。近20年来，西方发达国家普遍意识到了顾客满意度的作用、地位和意义，从定性和定量两个方面对CSD进行了系统研究。针对石油行业的特殊性，阐述了CSD对石油企业产品和服务质量定位的重要性，以ACSI为依据给出了石油企业用户满意度指数理论模型，并由此提出了石油企业用户满意度测评体系和方法。     

油气勘探投资项目评价指标的探讨

油气田勘探开发项目其技术经济特点不同于一般工业性项目，因其原油产量逐年递减，而收人也相对逐年减少，造成了项目单位成本逐年升高，利润指标逐年降低，文章就从油气田开发项目的一般生产规律和技术经济特点出发。初步研究了该类项目评价体系和基准值等相关问题，提出了初步的意见和建议，对决策工作能起到一定的作用。