Time dependency of trade union membership

Event-history analysis is used to model the time dependency of two decisions: the decision to join a trade union, and the decision to leave a trade union. We formulate two hypotheses with regard to these two decisions and parametric regression models are used to investigate these hypotheses. The process of joining a trade union can be described by a decreasing rate, using a Weibull. For the process of leaving a trade union, we suggest an increasing rate that decreases after several years, a process best described by a log-logistic model.     

Facility location under demand uncertainty: Response to a large-scale bio-terror attack

In the event of a catastrophic bio-terror attack, major urban centers need to efficiently distribute large amounts of medicine to the population. In this paper, we consider a facility location problem to determine the points in a large city where medicine should be handed out to the population. We consider locating capacitated facilities in order to maximize coverage, taking into account a distance-dependent coverage function and demand uncertainty. We formulate a special case of the maximal covering location problem (MCLP) with a loss function, to account for the distance-sensitive demand, and chance-constraints to address the demand uncertainty. This model decides the locations to open, and the supplies and demand assigned to each location. We solve this problem with a locate-allocate heuristic. We illustrate the use of the model by solving a case study of locating facilities to address a large-scale emergency of a hypothetical anthrax attack in Los Angeles County.     

基于单片机的四路抢答器的设计

抢答器是一种应用非常广泛的设备,在各类竞赛中,特别是做抢答题时,在抢答过程中,为了知道哪一组或哪一名选手先答题,必须要有一个系统来完成这个任务。如果在抢答过程中,只靠人的视觉是很难判断出哪组先答题。利用单片机来设计抢答器,使以上问题得以解决,即使有两组的抢答时间相差几微秒,也可分辨出哪组优先答题。抢答器已经发展到了用单片机的控制来实现其功能,制作过程简单,准确性与可靠性高,安装维护简单,而且功能齐全,电路简单,成本低,性能高,真正朝着更先进实用的方向发展。     

Tenure choice and the riskiness of non-housing consumption

This paper analyzes a household's choice of housing tenure within a dynamic utility maximization model that yields simple analytical results under uncertainty of income, housing prices, and rents. Given a housing consumption plan, we show that a decrease in the covariance between a household's earnings and housing rents increases the likelihood of ownership. A household who plans to remain in its home over a long period is more likely to own; a household who plans to remain in its home over a short period is more likely to rent. The higher the covariance between the user cost of a home and that of other properties a household is likely to consider in the future, the more likely the household is to own this home. These predictions of our model find support in recent empirical studies.     

Warranties as a device to extract rent from low‐risk users of a product

We develop a simple model that provides a new rationale for why a monopolist should bundle its product with a warranty even when all parties are risk neutral. In our model, a risk‐neutral monopolist faces two types of risk‐neutral consumers—low‐risk users that are unlikely to cause product failure and high‐risk users that are more likely to cause product failure. We find that when the firm fails to provide a warranty, a low‐risk user acquires a strictly positive rent by pretending to be a high‐risk user and receiving a price discount. By imposing a warranty, however, the monopolist can increase the price to high‐risk users, which in turn removes the incentive for a low‐risk user to pretend to be a high‐risk user, and the firm successfully extracts rent from the low‐risk user. Copyright © 2007 John Wiley & Sons, Ltd.     

Descending price multi-item auctions

We propose a simultaneous descending price auction mechanism to sell multiple heterogeneous items, each owned by a distinct seller, to a number of buyers. Each buyer has known private valuations on items, and wants at most one item. We show that if the sellers follow a descending price offer procedure and the buyers follow a greedy strategy for accepting the offers, the auction results in a nearly efficient allocation, and terminates close to a competitive equilibrium price vector. The descending price offer strategy of the sellers is close to a Nash equilibrium. However, we show that the buyers are better off waiting in our auction. There is a maximum limit (corresponding to the minimum competitive equilibrium price vector) till which they can wait without running into the risk of not winning any item. If the buyers wait within this limit, the prices can be brought arbitrarily close to a uniquely defined competitive equilibrium price vector.     

Local Venturing as Compassion Organizing in the Aftermath of a Natural Disaster: The Role of Localness and Community in Reducing Suffering

In contrast to models of compassion within existing organizations, this grounded theory study examines how ventures emerge relying on localness and community in direct response to ‘opportunities’ to alleviate suffering in the aftermath of a natural disaster. While a natural disaster is a surprising disruptive event devastating a local community, that local community is nested within a broader community, which can be a source of abundant resources. Ventures created in the aftermath of a natural disaster, given local knowledge and unencumbered by pre‐existing systems, procedures, and capabilities, are highly effective at connecting the broader community with the local community through customizing resources to meet victims' needs and to quickly delivering these resources to alleviate suffering.     

Emerging managerial competencies of professionals in the Tanzanian construction industry

The managerial competencies required by professionals in the construction industry in Tanzania to operate effectively in a business environment which is changing as a result of a transition from a socialist to a free-enterprise economy, economic liberalization, globalization and regionalization are explored through a qualitative study. The study reveals that local Tanzanian construction firms are finding it difficult to compete with foreign companies for projects. This is mainly because Tanzanian professionals lack the competencies required to compete and manage projects in a liberalized market economy.

The study thus highlights the need for Tanzanian construction professionals to acquire a better grasp of both occupational and organizational competencies. In this respect, it is suggested that they need post-experience training in order to acquire the competencies required to function successfully in a commercial environment.     

A mathematical approach to the boolean minimization problem

Any minimization problem involves a computer algorithm. Many such algorithms have been developed for the boolean minimizations, in diverse areas from computer science to social sciences (with the famous QCA algorithm). For a small number of entries (causal conditions in the QCA) any such algorithm will find a minimal solution, especially with the aid of the modern computers. However, for a large number of conditions a quick and complete solution is not easy to find using an algorithmic approach, due to the extremely large space of possible combinations to search in. In this article I will demonstrate a simple alternative solution, a mathematical method to obtain all possible minimized prime implicants. This method is not only easier to understand than other complex algorithms, but it proves to be a faster method to obtain an exact and complete boolean solution.     

Learning versus habit formation: Optimal timing of lockdown for disease containment

We analyze a model where the government has to decide whether to impose a lockdown in a country to prevent the spread of a possibly virulent disease. If the government decides to impose a lockdown, it has to determine its intensity, timing and duration. We find that there are two competing effects that push the decision in opposite directions. An early lockdown is beneficial not only to slow down the spread of the disease, but creates beneficial habit formation (such as social distancing, developing hygienic habits) that persists even after the lockdown is lifted. Against this benefit of an early lockdown, there is a cost from loss of information about the virulence and spread of the disease in the population in addition to a direct cost to the economy. Based on the prior probability of the disease being virulent, we characterize the timing, intensity and duration of a lockdown with the above mentioned tradeoffs. Specifically, we show that as the precision of learning goes up, a government tends to delay the imposition of lockdown. Conversely, if the habit formation parameter is very strong, a government is likely to impose an early lockdown.     

Updating and Estimating a Social Accounting Matrix Using Cross Entropy Methods

The problem in estimating a social accounting matrix (SAM) for a recent year is to find an efficient and cost-effective way to incorporate and reconcile information from a variety of sources, including data from prior years. Based on information theory, the paper presents a flexible 'cross entropy' (CE) approach to estimating a consistent SAM starting from inconsistent data estimated with error, a common experience in many countries. The method represents an efficient information processing rule-using only and all information available. It allows incorporating errors in variables, inequality constraints, and prior knowledge about any part of the SAM. An example is presented, applying the CE approach to data from Mozambique, using a Monte Carlo approach to compare the CE approach to the standard RAS method and to evaluate the gains in precision from utilizing additional information.     

Consumer cooperatives as an alternative form of governance: The case of the broadband industry

With a growing number of consumer cooperatives in non-agrarian industries such as energy and broadband, there is a need to better understand their emergence as a viable form of governance. In this context, the paper uses Mikami’s (2010) model on consumer cooperatives to explain their emergence as a result of their ability to generate additional equity financing through the membership market. It focuses on the motivations of consumers to financially contribute to a cooperative by examining the risks and benefits associated with the investment. Based on a survey of 759 consumers, it links their motivations for joining a cooperative to different forms of risks and benefits associated with the investment. It shows that the risks related to cost sharing and switching costs are important determinants for consumers. Other factors that affected the likelihood of joining a cooperative were expected benefits with respect to user network externalities and infrastructure gains.     

Waiting for innovation in the human resources department: Godot implements a human resource information system

The implementation of a new human resource information system (HRIS) represents a major form of planned organizational change for the Human Resource function, yet little research has been conducted on this issue. This article presents a longitudinal case study of the reactions of the Human Resource community in a large energy company to the planned implementation of a new corporate HRIS. Implementing an HRIS to enhance strategic and business decision-making has important organizational development implications. A new HRIS (1) represents an attempt to enable Human Resources to become more of a business partner, (2) changes the nature of HR work to encompass a greater information broker and decision support role, and (3) alters power dynamics and communication patterns involving Human Resources. Varying levels of resistance and ambivalence were found regarding the extent to which human resource information systems skills were valued as a critical competency. While there is a trend, toward attitudinal convergence within the human resource community, over time, the results suggest that user skill level may be more strongly related to variance in attitudes toward the value of a new HRIS than to hierarchical level or business unit affiliation. The study also found that face-to-face seminars were a significantly more effective intervention than was written communication in influencing favorable intention to use the HRIS.     

Experiments Testing Multiobject Allocation Mechanisms

This paper reports the results of over 130 auctions conducted under controlled conditions to examine the robustness of several auction mechanisms to allocate multiple objects. The simultaneous discrete auction process used by the Federal Communications Commission to allocate Personal Communications licenses was contrasted with a sequential auction and a combinatorial auction over a variety of demand conditions. In test environments created to check only the minimum competency of the procedures, the simultaneous discrete auction process produces highly efficient allocations, approaching levels similar to those found with a continuous form of the auction, and it outperforms a sequential auction. However, in environments created to stress test the procedures, a combinatorial auction outperforms the simultaneous discrete auction.     

The Impact of Information Availability on Destination Choice

Consider a population of agents who choose one among a set of destinations located along a rectilinear road. Each of these destinations has a certain utility, modeled by a random variable. We compare a situation where the agents have to explore the destinations to observe the value of their utilities, to a situation where they know these values beforehand. We show that more information yields a higher welfare to the agents, and also, perhaps counter‐intuitively, higher distance traveled.     

Modelling innovation support systems for regional development – analysis of cluster structures in innovation in Portugal

The present article offers a concise theoretical conceptualization and operational analysis of the contribution of innovation to regional development. The latter concepts are closely related to geographical proximity, knowledge diffusion and filters and clustering. Institutional innovation profiles and regional patterns of innovation are two mutually linked, novel conceptual elements in this article. Next to a theoretical framing, the article employs the regional innovation systems concept as a vehicle to analyse institutional innovation profiles. Our case study addresses three Portuguese regions and their institutions, included in a web-based inventory of innovation agencies which offered the foundation for an extensive database. This data-set was analysed by means of a recently developed principal coordinates analysis followed by a Logistic Biplot approach (leading to a Voronoi mapping) to design a systemic typology of innovation structures where each institution is individually represented. There appears to be a significant difference in the regional innovation patterns resulting from the diverse institutional innovation profiles concerned. These profiles appear to be region specific. Our conclusion highlights the main advantages in the use of the method used for policy-makers and business companies.     

Transfer pricing: Technical and productivity change within the firm

Use of transfer prices is regarded by many writers as an efficient means of management of multidivisional firms. Its use in effect creates an internal market for the firm. However, its value as a management technique isknown to be subject to a number of limitations of the type discussed in the general economic theory of market failure. Nevertheless, two important limitations of transfer pricing have been neglected in the literature: (1) imputed profit/loss based on optimal transfer prices can be a poor guide to the economic value of a division to a firm when market transaction costs are important (for instance, even if a division shows an imputed loss, it may not be optimal to dispose of it), and (2) transfer pricing can retard technical change, innovation and productivity enhancement within a division to the detriment of the firm as a whole. Both aspects are examined here.     

交叉网络外部性在证券交易所定价中的应用分析

本文利用双边市场理论对证券交易所进行实证检验和模型研究,采用格兰特因果检验方法对上海交易所数据进行了实证分析,研究结果表明相比上市公司而言,投资者是“鸡蛋相生”问题的关键点,因此根据实证结果提出扩大投资者规模是证券市场发展的关键所在.然后针对上市公司和投资者的自网络外部性特征及投资者内部之间交易的特点,采用模型研究得出较强的负自网络外部性使得交易所会降低上市公司的注册费来吸引公司;当注册费太高时,交易所会降低交易费来保留住投资者,反之亦然.     

Interpersonal team leadership skills

To say that a team leader's job is a tough one is certainly not saying enough. It is up to the team leader to manage a group of people to be individuals but yet work as a team. The team leader must keep the peace and yet create a revolution with this group all at the same time. The good leader will require a lot of education, training, and tons of practical application to be a success. The good news, however, is that the team leader's job is a rewarding one, one that they'll always feel good about if they do it right. How many of us get the opportunity to take a group of wonderful, thinking individual minds and pull from them ideas that a whole team can take to success? Yes, the job is indeed tough, but the paybacks are many.