The Bullwhip Effect—Impact of Stochastic Lead Time,Information Quality,and Information Sharing: A Simulation Study

We use a simulation model called ‘SISCO’ to examine the effects in supply chains of stochastic lead times and of information sharing and quality of that information in a periodic order‐up‐to level inventory system. We test the accuracy of the simulation by verifying the results in Chen et al. (2000a) and Dejonckheere et al. (2004). We find that lead‐time variability exacerbates variance amplification in a supply chain, and that information sharing and information quality are highly significant. For example, using the assumptions in Chen et al. (2000a) and Dejonckheere et al. (2004), we find in a numerical experiment of a customer‐retailer‐wholesaler‐distributor‐factory supply chain that variance amplification is attenuated by nearly 50 percent at the factory due to information sharing. Other assumptions we make are based on interviews or conversations with managers at large supply chains.     

The authority of Supreme Court precedent

We construct the complete network of 30,288 majority opinions written by the U.S. Supreme Court and the cases they cite from 1754 to 2002 in the United States Reports. Data from this network demonstrates quantitatively the evolution of the norm of stare decisis in the 19th Century and a significant deviation from this norm by the activist Warren Court. We further describe a method for creating authority scores using the network data to identify the most important court precedents. This method yields rankings that conform closely to evaluations by legal experts, and even predicts which cases they will identify as important in the future. An analysis of these scores over time allows us to test several hypotheses about the rise and fall of precedent. We show that reversed cases tend to be much more important than other decisions, and the cases that overrule them quickly become and remain even more important as the reversed decisions decline. We also show that the Court is careful to ground overruling decisions in past precedent, and the care it exercises is increasing in the importance of the decision that is overruled. Finally, authority scores corroborate qualitative assessments of which issues and cases the Court prioritizes and how these change over time.     

Dispersive ordering—Some applications and examples

A basic concept for comparing spread among probability distributions is that of dispersive ordering. Let X and Y be two random variables with distribution functions F and G, respectively. Let F ⁻¹ and G ⁻¹ be their right continuous inverses (quantile functions). We say that Y is less dispersed than X (Y≤ _disp X) if G ⁻¹(β)−G ⁻¹(α)≤F ⁻¹(β)−F ⁻¹(α), for all 0<α≤β<1. This means that the difference between any two quantiles of G is smaller than the difference between the corresponding quantiles of F. A consequence of Y≤ _disp X is that |Y ₁−Y ₂| is stochastically smaller than |X ₁−X ₂| and this in turn implies var(Y)≤var(X) as well as E[|Y ₁−Y ₂|]≤E[|X ₁−X ₂|], where X ₁, X ₂ (Y ₁, Y ₂) are two independent copies of X(Y). In this review paper, we give several examples and applications of dispersive ordering in statistics. Examples include those related to order statistics, spacings, convolution of non-identically distributed random variables and epoch times of non-homogeneous Poisson processes. This work was supported in part by KOSEF through Statistical Research Center for Complex Systems at Seoul National University. Subhash Kochar is thankful to Dr. B. Khaledi for many helpful discussions.     

Using response probability and ratio imputation in the estimation under callbacks

Although the response model has been frequently applied to nonresponse weighting adjustment or imputation, the estimation under callbacks has been relatively underdeveloped in the response model. We propose an estimator under callbacks using both the response probability and the ratio imputation and a replication variance estimator of the estimator. We also study the estimation of the response probability. A simulation study illustrates our technique.     

The Easterlin hypothesis in the recent experience of higher-income OECD countries: A panel-data approach

The Easterlin hypothesis emphasizes the effect of relative cohort size on fertility. Models based on the Easterlin hypothesis have performed well in explaining time series fertility data, although these results have been for long historical time series and have typically been restricted to single country studies. These models are not adequate to determine if the hypothesis still holds and if the success of the Easterlin hypothesis is an artifact of the time period chosen. We use panel data analysis and temporal causality tests to see of the Easterlin hypothesis holds for higher-income OECD countries. The results support the Easterlin hypothesis.All correspondence to Yongil Jeon. An earlier version, The Easterlin hypothesis in OECD countries, was presented at the annual conference of the European society for population economics, Bilbao, Spain, June 2002. We are grateful to two anonymous referees for their helpful comments. The usual caveat applies. Responsible editor: Junsen Zhang.     

A survey of simulation modeling techniques in production planning and control (PPC)

The manufacturing sector as a whole has undergone remarkable changes in terms of scale, complexity and technology over the past decades and this applies across most modern high-technology manufacturing such as electronics, semiconductor, aerospace and automotive industries. In order to remain competitive, manufacturers have to produce high-quality products at low cost, and at the same time retain sufficient flexibility and to meet rapidly changing customer demands. Production planning and control (PPC) is a key role which enables the manufacturer to gain visibility and control over all aspects of manufacturing activities. PPC in itself forms a subject of study, within which simulation techniques have proven themselves to be one of the most practical methodologies available to investigate and evaluate manufacturing issues. In this review paper, we focus on state-of-the art applications of simulation techniques in PPC to demonstrate their applicability to modern manufacturing issues. The review reports on academic publications on simulation applications in manufacturing from 2002 to 2014, incorporating surveys of peer-reviewed literature. The review covers three types of simulation techniques (system dynamic, discrete event simulation and agent-based simulation) and eight PPC issues (facility resource planning, capacity planning, job planning, process planning, scheduling, inventory management, production and process design, purchase and supply management). Literature survey is analysed on the basis of simulation application to PPC problems which can give a guideline for simulation technique selection and also can help for simulation modelling in PPC problemsWould you consider changing the term “modeling” to “modelling” in the title. Please check, and correct if necessary.     

韩中文学相遇的意义所在——第一届韩中作家论坛主题演讲稿

预定在今后10年间连续举办的韩中作家论坛的总主题是“和平”,第一届论坛的主题是“创伤与愈合”。对韩中两国来说,近几十年是个人遭受社会创痛并为治愈创痛而备受煎熬的过程。创伤的治愈只能通过揭露而不是掩盖创伤而实现。迄今为止,韩国文学一直致力于创伤的揭露,并为此对政治压制进行了勇敢抵抗。中国文学正式开始揭露现实创伤是在1980年以后。虽然韩中两国文学间差异与相似性共存,但更重要的是超越“韩国文学”和“中国文学”界限而存在的文学普遍性。两国文学间的对话因这种普遍性而成为可能,并使这种普遍性得以显现。     

BUNDLING ELECTRONIC JOURNALS AND COMPETITION AMONG PUBLISHERS

Site licensing of electronic journals has revolutionized the way academic information is distributed. However, many librarians are concerned about the possibility that commercial publishers might abuse site licensing by the practice of bundling. In this paper, we analyze how bundling affects journal pricing in the market of scientific, technical, and medical electronic journals and offer a novel insight on the bundling of a large number of information goods. We find that (i) when bundling is prohibited, surprisingly, industry concentration does not affect prices; (ii) when bundling is allowed, each publisher finds bundling profitable and bundling increases industry profits while reducing social welfare; and (iii) any merger among publishers already active in the market is profitable but reduces social welfare. (JEL: D4, K21, L41, L82)     

How Business Interests and Government Inaction Led to the Humidifier Disinfectant Disaster in South Korea: Implications for Better Risk Governance

Humidifier sterilizers were regarded as innovative and health-promoting products; they were widespread in South Korea until 2011. However, hospitals reported mysterious deaths, and a legal investigation in April 2016 found that hundreds of people have died due to use of the sterilizing disinfectant. This article takes up that topic, discussing the government's role in dealing with the risk regarding the humidifier disinfectant. We pay particular attention to the unequal nature of the uncertainty produced by the distorted socioeconomic structure. Through in-depth interviews with key informants and an examination of relevant documents from the government, civic groups, and newspapers, we find that the government had increasingly acknowledged the risk, yet their inaction failed to stop the high number of casualties, and they have only recently responded proactively. The uncertainty of the risk was unevenly distributed between companies, the government, experts, and citizens. We argue that the proactive and transparent role of the government with the precautionary principle could fix the unequal structure of knowledge production and preserve public health.     

韩国钢铁企业应对跨国并购的国际化经营战略——以Mittal Steel公司跨国并购为例

在经济全球化浪潮下，跨国企业并购日益加剧。从韩国Mittai Steel公司的跨国并购来看，尽管韩国钢铁企业拥有跨国并购的优势，但并没有处于主动的地位。为迅速适应跨国并购的国际化趋势，韩国钢铁企业应当积极通过跨国并购，进一步加强与钢铁生产相关企业以及同已经持有股份的国外企业之间的战略联盟。韩国政府也应当把跨国并购当做企业发展的重要战略，制定相关政策，积极支持企业跨国并购。