Benefactors and Beneficiaries: The Effects of Giving and Receiving on Cost‐Coalitional Problems

Motivated by supply chain collaborations in practice, we introduce a class of cost‐coalitional problems, which are based on a priori information about the cost faced by each agent in each set that it could belong to. Our focus is on problems with decreasingly monotonic coalitional costs. In this class of problems, we study the effects of giving and receiving when there exist players whose participation in an alliance always contributes to the savings of all alliance members (we refer to these players as benefactors), and there also exist players whose cost decreases in such an alliance (we call them beneficiaries). We use linear and quadratic norm cost games to analyze the role played by benefactors and beneficiaries in achieving stability of different cooperating alliances. We consider different notions of stability (the core and the bargaining set) and provide conditions for stability of an all‐inclusive alliance of agents which leads to minimum value of total cost incurred by all agents.     

Sequencing and Scheduling Appointments with Potential Call‐In Patients

This paper studies appointment scheduling for a combination of routine patients who book well in advance and last‐minute patients who call for an appointment later that same day. We determine when these same‐day patients should be scheduled throughout the day, and how the prospect of their arrivals affects the appointment times of the routine patients. By formulating the problem as a stochastic linear program, we are able to incorporate random and heterogeneous service times and no‐show rates, ancillary physician tasks, and appointment delay costs for same‐day patients who prefer to see the doctor as early as possible. We find that the optimal patient sequence is quite sensitive to the no‐show probabilities and the expected number of same‐day patients. We also develop two simple heuristic solutions to this combinatorial sequencing problem.     

Incentives in a Stage‐Gate Process

Many large organizations use a stage‐gate process to manage new product development projects. In a typical stage‐gate process project managers learn about potential ideas from research and exert effort in development while senior executives make intervening go/no‐go decisions. This decentralized decision making results in an agency problem because the idea quality in early stages is unknown to the executive and the project manager must exert unobservable development effort in later stages. In light of these challenges, how should the firm structure incentives to ensure that project managers reveal relevant information and invest the appropriate effort to create value? In this study, we develop a model of adverse selection in research and moral hazard in development with a go/no‐go decision at the intervening gate. Our results show that the principal's uncertainty regarding early‐stage idea quality—a term we refer to as idea risk—alters the effect of late‐stage development risk. The presence of idea risk can alter the incentives offered to the agent and may lead the principal to reject projects that otherwise seem favorable in terms of positive net present value. A simulation of early‐stage ideas, found through search on a complex landscape, shows that the firm can mitigate the negative effects of idea risk by encouraging breadth of search and high tolerance for failure.     

Improving Humanitarian Operations through Technology‐Enabled Collaboration

Humanitarian supply chains involve many different entities, such as government, military, private, and non‐governmental organizations and individuals. Well‐coordinated interactions between entities can lead to synergies and improved humanitarian outcomes. Information technology (IT) tools can help facilitate collaboration, but cost and other barriers have limited their use. We document the use of an IT tool to improve last‐mile supply distribution and data management in one of many camps for internally displaced persons after the January 2010 earthquake in Haiti, and we describe other current uses of technology in camp management. Motivated by these examples and the interest among humanitarian organizations in expanding the use of such tools to facilitate coordination, we introduce a cooperative game theory model and explore insights about the conditions under which multi‐agency coordination is feasible and desirable. We also outline an agenda for future research in the area of technology‐enabled collaboration in the humanitarian sector.     

Linking Process Quality and Resource Usage: An Empirical Analysis

Motivated by an increasing adoption of evidence‐based medical guidelines in the delivery of medical care, we examine whether increased adherence to such guidelines (typically referred to as higher process quality) is associated with reduced resource usage in the course of patient treatment. In this study, we develop a sample of US hospitals and use cardiac care as our context to empirically examine our questions. To measure a patient's resource usage, we use the total length of stay, which includes any additional inpatient stay necessitated by unplanned readmissions within thirty days after initial hospitalization. We find evidence that higher process quality, and more specifically its clinical (as opposed to its administrative) dimensions, are associated with a reduction in resource usage. Moreover, the standardization of care that is achieved via the implementation of medical guidelines, makes this effect more pronounced in less focused environments: higher process quality is more beneficial when the cardiac department's patient population is distributed across a wider range of medical conditions. We explore the implications of these findings for process‐oriented pay‐for‐performance programs, which tie the reimbursement of hospitals to their adherence to evidence‐based medical guidelines.     

Measuring the Contribution of Workers' Health and Psychosocial Work‐Environment on Production Efficiency

Increasingly many firms have started to implement programs intended to improve the workers' health and the psychosocial work‐environment, as well as other attributes of labor quality. Motivated by the need for evaluating to what extent the programs affect a firm's productivity performance, this study discusses a model for analyzing the contribution of labor quality attributes toward firm productivity. To assess the contribution from the labor quality attributes, we model firm productivity as the outcome of two separate processes within a firm: the physical production process and the labor quality process. Firm productivity is measured by a Malmquist‐like productivity index and is computed by Data Envelopment Analysis. Based on bootstrap methods we analyze potential statistical bias and provide bias‐corrected productivity estimates. The labor quality attributes are first modeled at an individual worker level as latent variables using Item Response Theory, and then aggregated to a firm‐level. The model is empirically validated using data from three manufacturing plants that participated in a coordinated worksite health promotion program. Over a 4‐year period (2000–2003), we observed a general improvement in efficiency of 2–5%, half of which could be attributed to an improvement in workers' health and psychosocial work‐environment. A key benefit with the model is that it is practical, easy to implement, and very fast to compute. The model also constructively contributes to the discourse on sustainability by providing a framework for deriving meaningful metrics and providing tangible measurements on the effect of sustainability‐related issues.     

Optimal Inventory Control with Retail Pre‐Packs

A pre‐pack is a collection of items used in retail distribution. By grouping multiple units of one or more stock keeping units (SKU), distribution and handling costs can be reduced; however, ordering flexibility at the retail outlet is limited. This paper studies an inventory system at a retail level where both pre‐packs and individual items (at additional handling cost) can be ordered. For a single‐SKU, single‐period problem, we show that the optimal policy is to order into a “band” with as few individual units as possible. For the multi‐period problem with modular demand, the band policy is still optimal, and the steady‐state distribution of the target inventory position possesses a semi‐uniform structure, which greatly facilitates the computation of optimal policies and approximations under general demand. For the multi‐SKU case, the optimal policy has a generalized band structure. Our numerical results show that pre‐pack use is beneficial when facing stable and complementary demands, and substantial handling savings at the distribution center. The cost premium of using simple policies, such as strict base‐stock and batch‐ordering (pre‐packs only), can be substantial for medium parameter ranges.     

Introduction to the Special Issue on Humanitarian Operations and Crisis Management

The Genesis of this Special Issue came from the Board of the POMS College on Humanitarian Operations and Crisis Management (HO&CM). It was seen as a necessary initiative to define the field and examine research opportunities. This Special Issue shows that humanitarian operations pose challenges for P/OM researchers and practitioners that differ markedly from those of conventional supply chains associated with profitable enterprises. On the basis of the eight articles in this Special Issue, we have described and demonstrated the unique characteristics of the POM/HO&CM interaction. We have also identified those attributes that tend to overlap with conventional aspects of POM. In addition to wanting to be cost effective, the issue of equity fairness is pervasive in humanitarian operations, and so is the need to always base considerations on “last‐mile logistics,” that is, getting aid to those in most need. Research is essential to determine how to train researchers to scout out and map the territory of the real problems. One of the most vexing problems is the lack of robust data in the humanitarian domain which is as richly varied as the types of disasters that can occur.     

影响中低层灵活就业群体实现就业的推拉因素分析——以3120名中低层灵活就业人员的调查为例

本文运用推拉理论对影响中低层灵活就业群体最终实现就业的因素进行分析.作者认为中低层灵活就业的实现是原行业的"推力"大于"拉力",而灵活就业"拉力"大于"推力"合力作用的结果.但由于个体就业意愿和就业环境因素对推力和拉力效应的制约,必须营造良好的制度环境,增大灵活就业的拉力作用.     

Immigration,ethnicity, and the loss of white students from California public schools, 1990–2000

This article investigates whether and the extent to which “white flight” from Hispanic and Limited English Proficient (LEP) students has been occurring in California’s public schools and further, examines the level (school or district) on which “white flight” may operate. Using school-level administrative data from the California Department of Education from 1990 to 2000, we estimate exponential growth rate models of white enrollment with school-level fixed effects. The results shed light on the implications of immigration for school segregation in the United States. The analysis indicates that white enrollment declined in response to increases in the number of Spanish-speaking LEP and Hispanic students, and that “white flight” from LEP or Hispanic students occurred more at the district than the school level in the case of primary schools, and at the school level for secondary schools. In addition, schools with higher percentages of Spanish LEP students in the school than the district, and with higher percentages in the district relative to the county, experienced greater losses in white enrollments than other schools, thus suggesting that higher levels of segregation in the wider metropolitan area accelerate white flight.