Age-test Markov chains for drug testing and detection

Random urinalysis strategies stratified by time since the last test are characterized with a set of Markov chain models. The probability of a person being tested depends on the amount of time since the person's last test. The Nuclear Regulatory Commission (NRC) has proposed a two strata drug testing strategy based on time since last test. The proposal included a high testing rate for people not yet tested in a given time period and a low testing rate for people testing negative in a given time period. Southern California Edison has implemented a variation of the NRC proposal. These strategies can be modeled within a Markov chain framework. Time to detection is calculated as a function of testing probabilities and drug usage levels. Drug user gaming strategies are discussed with illustrations. These models are implemented as part of a U.S. Navy drug policy analysis system.     

Ex ante assessment of the returns to livestock disease control in Indonesia

Agriculture's importance in the process of economic growth highlights the role of sustained advances in farm production practices by improving the quantity and quality of farm products. In this context, investment in improved agricultural technology continues to be an important avenue of assistance to the developing countries. However, the increased resource pressures facing both aid donors and recipients have emphasised the need for the prior assessment of the potential benefits of aid projects to assist effective aid planning and management. Here, the main requirements are to establish viable project goals for translation into effective programmes, to predict the likely project impacts, and to evaluate the potential benefits and costs of adopting the project's outcomes. An ex ante assessment of assistance in controlling a major livestock disease in Indonesia's eastern islands is described in this paper. The annual net benefits from controlling this disease ranged between $A0.45 and $A2.5 million according to the mortality rate reduction achieved. The benefits were shared between beef producers and consumers according to the market elasticity conditions assumed.     

Canadian Strike Replacement Legislation and Collective Bargaining: Lessons for the United States

Opponents of U.S. and Canadian strike replacement legislation contend that restricting the use of strike replacements significantly alters bargaining power and increases strike activity. This article uses data on Canadian manufacturing collective-bargaining agreements to investigate these hypotheses. Although a general ban on strike replacements is found to be associated with longer strikes, little evidence is found to suggest that banning permanent strike replacements significantly influences strike incidence, strike duration, or negotiated wages.     

Estimating Willingness to Pay for Improved Water Quality in the Presence of Item Nonresponse Bias

This article deals with the problem of item nonresponse in contingent valuation surveys using a payment-card method, by applying a grouped-data sample-selection estimation technique that is capable of imputing the missing values conditional upon a respondent's decision to answer a willingness-to-pay question. The advantage of the technique lies in its ability to utilize all of the information in the sample, permitting a more efficient estimation in the presence of item nonresponse bias. The major determinants of willingness to pay appear to be household income, number of children, education, perception of existing water quality, and identification with environmental issues.     

Directly measuring early exercise premiums using American and European S&P 500 Index options

The Chicago Board Options Exchange concurrently listed European‐style and American‐style options on the Standard and Poor's 500 Index from April 2, 1986 through June 20, 1986. This unique time period allows for a direct measurement of the early exercise premium in American‐style index options. In this study, using ask quotes, we find average early exercise premiums ranging from 5.04 to 5.90% for calls, and from 7.97 to 10.86% for puts. Additionally, we are able to depict a potentially useful functional form of the early exercise premium. As in previous studies, we find some instances of negative early exercise premiums. However, a trading simulation shows that traders must be able to trade within the bid–ask spread to profit from these apparent arbitrage opportunities. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:287–313, 2003     

B‐TO‐B E‐COMMERCE: A CONTENT ANALYTICAL ASSESSMENT OF MOTOR CARRIER WEBSITES

An Internet presence is a critical early component in the process of building towards a fully operational and unified e‐commerce strategy. E‐commerce has significantly impacted logistics/supply chain strategies and the development and implementation of a website have become key issues for many firms within the transportation industry. This study provides an overview of website content within the motor carrier industry. Content analysis was used to assess the site design, informational content, and the interactive content of 152 motor carrier websites, and to compare the features offered on the Top 100 motor carrier firm websites with those offered on the sites of smaller carrier firms.     

MANAGING VENDOR INVENTORY IN A DUAL LEVEL DISTRIBUTION SYSTEM

Collaborative arrangements among members of the supply chain have received a great deal of interest in recent years as a means of reducing costs. One such arrangement is vendor managed inventory (VMI). VMI allows the vendor to make decisions concerning the quantity and timing of deliveries to the retailer. Such an arrangement offers the potential of a more efficient supply chain by removing the negative effects of retail ordering policies. A thorough review of the literature was conducted to identify factors likely to impact the performance of a VMI partnership. Computer simulation was used to study the effects of these factors from both the vendor's and retailer's perspectives. The results lend insight into the performance of VMI and guidance for managers as to the environments in which VMI is most effective.     

RELATIONSHIP MAGNITUDE AND ITS ROLE IN INTERORGANIZATIONAL RELATIONSHIP STRUCTURE

Close relationships between and among supply chain members are becoming more prevalent. However, there is lack of agreement in the literature and in practice concerning the characteristics of different interorganizational relationships. The resultant confusion is an obstacle to the progression of research and could cause problems among firms in a supply chain. Based on previous research and an exploratory study conducted with company executives responsible for supply chain management activities, this article seeks to introduce the concept of relationship magnitude (i.e., the extent or degree of closeness or strength of the relationship) and differentiate it from relationship type (i.e., classes of relationships that share common traits). Implications for managers and opportunities for future research are provided.     

我国A股、B股市场并轨的前景探析

B股市场的前途问题是一个困扰市场参与者的主要问题,而前途的不明朗源于B股市场定位的困惑和功能失调。筹资功能方面,1991～2004年12月B股市场通过股票发行总计筹资50.03亿美元,通过配股筹资3.27亿美元,而同期A股市场对应的数据是5695.7亿元和2276.74亿元,而且最近3年B股市场的