A Risk-Benefit Analysis of French High Fish Consumption: A QALY Approach

The health risk and the nutritional benefit of a food are usually assessed separately. Toxicologists recommend limiting the consumption of certain fish because of methylmercury; while nutritionists recommend eating more oily fish because of omega 3. A common evaluation is imperative to provide coherent recommendations. In order to evaluate the risks along with the benefits related to fish consumption, a common metric based on the quality-adjusted life year (QALY) method has been used. The impact of a theoretical change from a medium n-3 PUFAs intake to a high intake is studied, in terms of the cardiovascular system (CHD mortality, stroke mortality and morbidity) and on fetal neuronal development (IQ loss or gain). This application can be considered as a sensitive analysis of the model used and looks at the impact of changing the dose-response relationships between cardiovascular diseases and n-3 PUFAs intakes. Results show that increasing fish consumption may have a beneficial impact on health. However, the confidence interval of the overall estimation has a negative lower bound, which means that this increase in fish consumption may have a negative impact due to MeHg contamination. Some limits of the QALY approach are identified. The first concerns determination of the dose-response relationships. The second concerns the economic origins of the approach and of individual preferences. Finally, since only one beneficial aspect and one risk element were studied, consideration should be given to how other beneficial and risk components may be integrated in the model.     

基于JIT配送的3PL运输协调调度问题建模与分析

近年来,随着第三方物流(Third Party Logistics,3PL)的日益成熟,其服务的专业性越来越高。相当数量的制造商们把产品的运输与配送外包给3PL以缩短订单处理的时间。本文研究Just-in-Time(JIT)背景下由3PL主导的供应链中3PL协调调度问题。3PL给出运输工具的出发、到达时间、可用的运载容量及相应的价格。制造商根据其生产调度和订单配送要求,有选择的使用3PL的运输资源,以最小的成本达JIT配送的目的。本文建立了该问题的数学模型,并证明了相应的计算复杂度。最后通过仿真实验验证计算复杂度。     

Revisiting the cooperation–competition paradox: A configurational approach to short- and long-term coopetition performance in business networks

Cooperation and competition are often viewed as incompatible, antagonistic forces, thus are operationalized as two extremes on a continuum. However, they can coexist and even enable each other, thus may be operationalized as orthogonal constructs. We address this contradictory phenomenon by developing a more granular view of the cooperation–competition paradox. Building on interdisciplinary research, we develop a three-dimensional model of relational space (fairness–opportunism, sharing–control, and engagement–rivalry), providing a novel tool with which to investigate the paradoxical interplay between cooperation and competition through eight operationalizable configurations. Using fuzzy-set qualitative comparative analysis (fsQCA), we test our model by assessing how different configurations of interfirm relationships influence the short- and long-term success of a sample of 217 firms. Our findings show that only two of the eight possible relational configurations are associated with firm success, one in both the long and short term, and the other in the short term only.     

基于系统动力学第三方直通集配中心模式研究

采用定性分析与系统动力学建模定量研究相结合的研究方法,首先对供应链库存管理的第三方直通集配中心模式做了较为系统的分析和界定;其次,建立了第三方直通集配中心模式下的供应链系统动力学模型;最后,对第三方直通集配中心模式供应链库存管理案例进行了仿真分析,证明了该模式相对分散式VMI模式的比较优势,并对第三方直通集配中心的运营策略提出了优化建议.     

RAILROADS AND GROWTH IN PRUSSIA

We study the effect of railroad access on urban population growth. Using GIS techniques, we match triennial population data for roughly 1,000 cities in 19th‐century Prussia to georeferenced maps of the German railroad network. We find positive short‐ and long‐term effects of having a station on urban growth for different periods during 1840–1871. Causal effects of (potentially endogenous) railroad access on city growth are identified using propensity score matching, instrumental variables, and fixed‐effects estimation techniques. Our instrument identifies exogenous variation in railroad access by constructing straight‐line corridors between nodes. Counterfactual models using pre‐railroad growth yield no evidence to support the hypothesis that railroads appeared as a consequence of a previous growth spurt.     

POLITICAL SELECTION IN CHINA: THE COMPLEMENTARY ROLES OF CONNECTIONS AND PERFORMANCE

Who becomes a top politician in China? We focus on provincial leaders—a pool of candidates for top political office—and examine how their chances of promotion depend on their performance in office and connections with top politicians. Our empirical analysis, based on the curriculum vitae of Chinese politicians, shows that connections and performance are complements in the Chinese political selection process. This complementarity is stronger the younger provincial leaders are relative to their connected top leaders. To provide one plausible interpretation of these empirical findings, we propose a simple theory in which the complementarity arises because connections foster loyalty of junior officials to senior ones, thereby allowing incumbent top politicians to select competent provincial leaders without risking being ousted. Our findings shed some light on why a political system known for patronage can still select competent leaders.     

Critical success factors in managing modular production design: Six company case studies in Hong Kong, China, and Singapore

Many researchers have explored the advantages of modular product design, its design methods and its effects on product performance. Modular design is, for example, required for product platform, mass customization and postponement in order to achieve greater product variety and differentiation. However, a few empirical studies explicitly examine how to coordinate modular product design in a managerial way. This paper addresses it by conducting multiple case studies with six companies which have successfully adopted modular product design for five years. Seven critical factors are explored in the management of modular product design. These are pre-defined product advantage, selectively used design rules, module definition, system integration, technological newness, internal communication, and supplier and customer involvement. While most of the literature studies the technical dimension of modular design within a firm, this study focuses on the managerial side across the supply chain. It gives new insights on how to manage modular product design and proposes future research opportunities.     

An assessment framework based on social perspectives and Analytic Hierarchy Process: A case study on sustainability in the Japanese concrete industry

This research introduces a framework for assessing concrete sustainability which is based upon the concept that technology is defined by stakeholders’ perspectives and which applied Analytic Hierarchy Process to translate these perspectives into quantifiable assessment values. A survey was conducted to identify important criteria, and several “design scenarios” were introduced which represent different value systems by varying criteria importance. Concrete materials with varying environmental impact were then assessed to observe the effect of different value systems and material properties, and it was found that the concrete with better properties was generally selected as most sustainable regardless of the design scenario.     

The Economic Efficiency of Sampling Size: The Case of Beef Trim

The economically optimal sample size in a food safety test balances the marginal costs and marginal benefits of increasing the sample size. We provide a method for selecting the sample size when testing beef trim for Escherichia coli O157:H7 that equates the averted costs of recalls and health damages from contaminated meats sold to consumers with the increased costs of testing while allowing for uncertainty about the underlying prevalence rates of contamination. Using simulations, we show that, in most cases, the optimal sample size is larger than the current sample size of 60 and, in some cases, it exceeds 120. Moreover, lots with a lower prevalence rate have a higher expected damage because contamination is more difficult to detect. Our simulations indicate that these lots have a higher optimal sampling rate.     

FINANCIAL CONSTRAINTS AND INNOVATION: WHY POOR COUNTRIES DON'T CATCH UP

This paper examines micro‐level channels through which financial development can affect such macroeconomic outcomes as level of income. Specifically, we investigate theoretically and empirically how financial constraints affect a firm's innovation activities. Theoretical predictions are tested using unique firm survey data, which provide direct measures for innovations and firm‐specific financial constraints, as well as information on shocks to firms' internal funds that serve as firm‐level instruments for financial constraints. We find unambiguous evidence that financial constraints restrain the ability of domestically owned firms to innovate and hence to catch up to the technological frontier.