THE EFFECT OF ACCESS TO IMPROVED WATER SOURCES AND SANITATION ON ECONOMIC EFFICIENCY: THE CASE OF SUB‐SAHARAN AFRICAN COUNTRIES

This paper evaluates the effect of access to improved water sources and sanitation on 41 sub‐Saharan African (SSA) countries' economic efficiency and growth. For this reason data envelopment analysis (DEA), bootstrap techniques and probabilistic approaches are used. The empirical results indicate that SSA countries' economic efficiency is positively influenced by the access of population both on improved water sources and sanitation. Finally, when the provision of access to improved water sources is provided to more than 50% of the population, the positive effect on countries' economic efficiency is much greater compared with the effect of providing sustainable access to improved sanitation to the same proportion of population.     

以建构主义理论为基础的语言僵化实证研究

僵化是第二语言学习的普遍现象,但是在建构主义理论基础上针对僵化现象的实证研究并不多见。以建构主义理论为依据,通过分析、对比在实验前后的调查结果,探索建构主义学习论能否有效缓解或解决中介语僵化问题,从而为解决语言僵化现象提供有效的解决方法。     

MSCT后处理技术显示冠状动脉狭窄形态与范围的比较研究

目的:比较研究多层螺旋CT后处理技术显示冠状动脉狭窄的形态与范围。方法:采用飞利浦多层螺旋CT工作站对随机抽取的120例病人冠状动脉采集图像进行重组,由2位影像医师比较多平面重组(multi-planar reformation,MPR)和CT仿真内窥镜(CT virtual endoscopy,CTVE)两种后处理技术对粥样硬化斑块形态的显示能力,同时比较MPR、曲面重建(curved planar reformat,CPR)和容积再现技术(volume rendering technique,VRT)在显示狭窄范围上的差异。结论:多层螺旋CT冠状动脉成像常用的后处理方法中,MPR血管轴位图最适合进行冠状动脉狭窄形态的研究;CPR最适合研究血管狭窄的范围。     

大型钢模壳的开发与施工技术

中国建筑文化中心展厅及以上的楼层 ,设计采用了适合公共建筑的无粘结预应力双向密肋板结构体系 ,取得了很好的综合效益。施工在选用支模方案时 ,开发了大型钢模壳 ,代替了现常用的塑料模壳、玻璃钢模壳 ,不仅为本工程降低了投资、提高了外观质量 ,且为今后推广这类结构时 ,提供了实践经验     

Risk-sharing and Growth: The Role of Precautionary Savings in the "Education" Model

While the "risk amelioration" literature suggests that risk-sharing channels savings into risky but productive technologies and hence favours growth, models focused on precautionary savings reverse this conclusion. We solve, by means of numerical techniques, a model based on human capital accumulation through education, and find that the increase in precautionary savings makes labour more productive in the goods sector and draws resources from education, which is the "growth leading" activity. Hence, we establish a result favourable to financial integration, even in a model where precautionary savings play an important role.     

Job Classification for the Purpose of Making Optimal Decisions Concerning Management Control

The job classification literature has been dominated by a micro‐level orientation reflective of the needs of specialists in human resources. In contrast, we take a multidisciplinary approach involving both micro‐ and macro‐level variables to propose a relatively simple system comprised of four job classes. Our model isintended to inform management as to the type and mix of controls (e.g., centralization, formalization, and various human resources policies) that could be applied to different job types to optimally promote the overall goals of the organization. Fuzzy numbers analysis is employed to illustrate the application of the system using four jobs in a car dealership in Spain. Copyright © 2012 ASAC. Published by John Wiley & Sons, Ltd.     

ExpertLens: A system for eliciting opinions from a large pool of non-collocated experts with diverse knowledge

The complexity of policy decision-making raises the need to elicit opinions from large and heterogeneous groups of stakeholders with broad and diverse sets of expertise. Existing options for elicitation include small face-to-face panels of experts by using the Nominal Group Technique (NGT), large Delphi panels whose members do not interact with each other face-to-face, and crowdsourcing, which involves an open call for input issued to a large community of people. In an attempt to close the gap between the practical needs of policy makers and the methodological challenges associated with eliciting opinions of large, diverse, and distributed groups, we have developed a new online elicitation system and methodology called ExpertLens. By optimizing the direct interactions of NGT with the larger number of Delphi participants and the wisdom of “selected crowds,” our approach is designed to save on the costs associated with traditional expert panels, while increasing accuracy in elicitation by reducing the potential for group process losses that can occur in large, diverse, and non-collocated panels whose members interact via asynchronous online discussion boards. The ExpertLens approach is iterative, does not require participants to develop consensus, and determines what the group “thinks” by statistically analyzing data collected in all rounds of the elicitation. This paper describes the ExpertLens system and methodology, briefly discusses recent ExpertLens trials, provides conceptual arguments for why it is an appropriate model for eliciting expert opinions, illustrates its main components and analytics by using an infrastructure investment example, and discusses a research agenda for testing the underlying tenets of the ExpertLens approach.     

Weighted utility optimization of the participating endowment contract

ABSTRACT

In a participating endowment contract, the special loss compensation and profit sharing mechanism leads to heterogeneous benchmarks to distinguish the gain and loss for the policyholder's and the insurance company's S-shaped utilities. Because of the intense competition among the insurance companies and the requirement of the regulators, the benefits of the policyholders should be considered. As such, choosing the weighted utility of the two counterparts as the optimization objective is a rational setting. This setting induces a non-HARA (hyperbolic absolute risk aversion) and non-concave objective utility whose exact concavity and convexity are unknown. The difficulties not only come from this highly non-concave optimization problem, but also exist in the implicit integration of the optimum when solving the expected utilities of the two counterparts. We originally design an identification method to establish two categories of concave envelopes to solve the optimization problem, and propose an innovative numerical integration by substitution technique to deal with the implicit integration problem. The numerical simulation results recognize the existence of Pareto improvement of the two counterparts, which shows that the utilities of the policyholder and the insurance company can be simultaneously improved by switching into the weighted objective and appropriately amending the contract.     

The effectiveness of economic sanctions with application to the case of Iraq

In a recent article, San Ling Lam (1990) used a probit estimation technique to re-examine the conclusions of Hufbauer, Schott and Elliott (1985) regarding the effectiveness of economic sanctions in achieving foreign policy goals. While Lam's criticisms of the HSE methodology are valid, the results of the model developed here differ in lending support to the HSE conclusions. In addition, the model can be used to predict the probability of sanctions contributing to a peaceful resolution of the recent Middle East crisis. The predicted probabilities of success in the Iraq case were above average and well above 50 percent.     

International trade and the relative dispersion of industrial wages and production techniques in 14 OECD countries, 1970–1985

The Factor Price Equalization theorem implies that freer trade would narrow the gap in returns to similar productive factors across countries over time. To determine the empirical relevance of this implication, data for 11 industries in 14 countries over the period 1970–1985 are investigated. Moreover, the paper examines the data for seven industries in the nontrade sector. Regression analyses suggest that the industry-level wages across countries are significantly influenced by the relative dispersion of production techniques at the industry level and, to a lesser extent, by international trade. The estimation of a wage model indicates that the diffusion of technology may have also played a role in the apparent convergence of wages. The findings of this paper suggest that FPE is capable of explaining the cross-country variation in returns to productive factors.