DYNAMIC DISAGGREGATE CHOICE MODELS,WITH AN APPLICATION IN TRANSPORTATION

A standard assumption of disaggregate mode-choice models is that an individual faced with a choice among several available alternative transportation modes compares their utilities. These utilities are almost always expressed as a linear composite measure of various perceived benefits which are assumed constant. However, the individual's perceptions change as he learns, acquires new habits, or adapts to different physical, economic, and social circumstances. In order to account for these changes, two dynamic models of model-choice behavior are developed herein. These two models are based on two common postulates. (1) One alternative is preferred over another only if the absolute difference in their utilities exceeds a positive constant; otherwise, the decision maker is indifferent toward the two alternatives. (2) If an alternative is preferred, it will be chosen with certainty. In the indifference state, the individual is postulated to randomly choose one of the two alternatives (Model 1) or choose the same alternative as was most recently chosen (Model 2). Choice probabilities derived from these two models are shown to differ from those obtained using the conventional logit model. If there is a strong loyalty toward a mode, the logit model underestimates its choice probability when that mode is less attractive than the competing mode. The results are illustrated using numerical examples.     

Quality upgrading and restrictive hiring practices in unionized jobs

Most previous work has suggested that unionized employers upgrade labor quality of new hires, but has been silent on the behavior of unions when they control hiring. In this paper, it is argued that unions also have the incentive to upgrade quality, but to an extent less than or equal to upgrading by employers. Empirical support for this argument is provided using data from the National Longitudinal Surveys of young men and young women, in conjunction with an industry measure of union control over hiring. Years of schooling and worker IQ measure labor quality. The author may be contacted at 9271-B Jamison Avenue, Philadelphia, PA 19115. She thanks her dissertation committee members Masanori Hashimoto, Patricia Reagan, and especially Donald Parsons, for their detailed comments, and seminar participants at the Ohio State University for helpful suggestions on previous drafts.     

The noncentral bivariate chisquared distribution and extensions

The distribution of certain correlated noncentral chisquared variates P, Q, is termed the noncentral bivariate chisquared distribution. Moment generating functions of the distributions of (P, Q), (P+Q) and other quadratic forms have been obtained. A relationship to the linear case of the noncentral Wishart distribution is indicated. Convolution properties and applications are presented.     

Operations Management Opportunities in Technology Commercialization and Entrepreneurship

The field of Production and Operations Management (POM) is increasingly perceived as a rigorous but narrow field, antiquated and not very relevant to the current challenges and concerns of managers in job‐creating growth companies vital to our economies. I argue that a narrower positioning of POM in the past is responsible for its perceived limited utility to growth firms and global economies. POM at its core is about “doing more with less,” which is very well aligned with the context and needs of resource‐constrained entrepreneurial companies. My discussion is focused on how the research paradigm of POM is and can be relevant to meeting the emerging challenges of growth companies of tomorrow. Specifically, I examine how POM can help meet the needs of these organizations to become scalable and sustainable. The objective is to stimulate thought and discussion and encourage early‐stage POM scholars to seriously consider the contexts of technology commercialization, entrepreneurship, and growth companies as avenues for future research.     

Toward a prediction of third-world immigrants into Canada, 1973-1985

The author examines trends in migratory movements to Canada between 1949 and 1972 in an attempt to determine the statistical regularity of immigration from developing countries and to predict the probable number of third world immigrants to Canada for the period 1973-1985. The effects on migration of political factors and of variables associated with the area of origin are studied (SUMMARY IN FRE, SPA)     

A Retrospective Look at Production and Operations Management Articles on New Product Development

We present a retrospective look at the articles on New Product Development that appeared in the first 50 issues of Production and Operations Management (POM). We discuss some of the strengths and weaknesses of this POM literature stream. This article is not intended to be a literature review or an exhaustive review of the articles. Rather, we seek to identify new opportunities for rigorous and relevant research, research that has the potential of differentiating and enhancing POM within the Operations Management literature.     

INTEGRATED COMPONENT AND SUPPLIER SELECTION FOR A PRODUCT FAMILY

This paper examines the reduction in complexity of a product family through product design. By leveraging the commonalities among products in a family, the decision support methodology presented in the paper helps choose components and suppliers that minimize the sum of design, procurement, and usage costs. The problem of integrated component and supplier selection is conceptualized and formulated as an integer-programming model. Analysis of the model yields two properties, complete and continuous replacement, which form the basis of a heuristic procedure. Computational tests show that the heuristic provides results close to the optimal solution and can be used for selecting components and suppliers. Application of the model to an industrial problem is discussed.     

Distributing a Product Line in a Decentralized Supply Chain

Although there is a rich literature on single product distribution in decentralized supply chains, the incentive problems that arise in distributing a product line have largely not been investigated. In practice, most manufacturers distribute a line of products with different features and qualities and not just a single product. Consider a manufacturer who distributes a product line through competing downstream retailers. In this setting, we investigate how and why the retailers' price and inventory decisions deviate from the centrally optimal decisions. Due to substitution between different product variants, as well as between different retailers, the incentive problems associated with distributing a product line are more complicated than that of distributing a single product. We characterize retailers' incentive distortions under a residual‐claimancy contract, and construct contracts that achieve channel coordination. We show that retail price floors or inventory buybacks, appropriately tailored to each product variant, are among the contracts that can achieve coordination. Using numerical simulations, we demonstrate how the optimal contract terms (such as wholesale prices and buyback prices) for each variant are influenced by the parameters of an underlying consumer choice model.     

Team Dispersion,Information Technology,and Project Performance

The impact of information technology (IT) on the performance of distributed projects is not well understood. Although prior research has documented that dispersion among project teams has an adverse effect on project performance, the role of IT as an enabler of communication to bridge the spatial distance among team members in distributed networks has not been empirically studied. We focus on the role of IT as a moderator of the relationship between team dispersion and project performance using projects as the unit of analysis. We find that IT mitigates the negative effect of team dispersion on project performance, especially in high information volume projects. Our central contribution is the development of an empirically tested model to improve the understanding of the operational impact of IT as a vehicle to bridge spatial dispersion among distributed teams that are engaged in knowledge‐intensive work.