THE EFFECT OF SELECTIVE INS MONITORING STRATEGIES ON THE INDUSTRIAL EMPLOYMENT CHOICE AND EARNINGS OF RECENT IMMIGRANTS

One effect of 1986's immigration reform was to make INS inspection of firms more costly relative to other industries. In response, we suggest, the INS refocused its enforcement efforts toward industries with a higher concentration of illegals per establishment, especially manufacturing. We test this hypotheses and model the effects of a selective monitoring strategy on the employment choice and wages of illegal workers. We find evidence of selective monitoring by the INS and that this policy has redistributed illegal workers from closely to weakly monitored industries. Specifically, we find a shift from the higher-paying manufacturing sector to the agricultural.     

Evaluation of a class-based storage scheduling technique applied to dual-shuttle automated storage and retrieval systems

Research to improve the performance of automated storage and retrieval systems has concentrated on developing more effective system designs or scheduling control programs to reduce the time a shuttle spends travelling in a rack. Sarker et al. (1991) showed that a dual-shuttle AS/RS operating under a nearest-neighbour scheduling model would significantly improve system throughput performance over a single-load shuttle system. The study was limited in that it only considered dual-shuttle improvements under the nearest-neighbour model. This research exploits the benefits of a dual-shuttle system by integrating the technology with a more effective scheduling technique, the class-based storage model, for reducing the shuttle travel time. The dual-shuttle, class-based storage model produced a significant reduction in shuttle travel time and thus higher throughput results over the dual-shuttle, nearest-neighbour model. This study further supports the premise that a dual-capacity shuttle is an effective way of improving the productivity of an automated storage and retrieval system.     

THE EFFECT OF CADAVERIC KIDNEY DONATIONS ON LIVING KIDNEY DONATIONS: AN INSTRUMENTAL VARIABLES APPROACH

Transplantation is notable for the degree to which resources are allocated via administrative rather than market mechanisms. However, non‐monetary incentives still permeate the system. Using instrumental variable regression, we estimate the substitution patterns between cadaveric and living kidney donations in the United States from 1988 to 2008. On average, a decrease of two to five cadaveric donations causes living kidney donations to increase by one. Disaggregating living donors into blood‐related and non‐blood‐related donors, the strongest effect is found among non‐blood‐related donors known to the organ recipient. A 1% increase of cadaveric donations decreases living donations from this group by 1.54%. (JEL D62, D64, I1)     

Models,methods and tools for interorganizational logistics operations

Enterprise modelling is today one of the key techniques to improve the performances of an enterprise. This paper first defines enterprise modelling techniques as compared to BPR techniques. Then the latest developments in GRAI methodology are presented. Finally, examples of industrial applications are presented for three methods: GIM (GRAI Integrated Method) for re-engineering, GIMSOFT for the choice of an ERP software package and ECOGRAI for the design and implementation of performance indicator system.     

Bayesian Robustness Modelling of Location and Scale Parameters

Abstract. The modelling process in Bayesian Statistics constitutes the fundamental stage of the analysis, since depending on the chosen probability laws the inferences may vary considerably. This is particularly true when conflicts arise between two or more sources of information. For instance, inference in the presence of an outlier (which conflicts with the information provided by the other observations) can be highly dependent on the assumed sampling distribution. When heavy‐tailed (e.g. t) distributions are used, outliers may be rejected whereas this kind of robust inference is not available when we use light‐tailed (e.g. normal) distributions. A long literature has established sufficient conditions on location‐parameter models to resolve conflict in various ways. In this work, we consider a location–scale parameter structure, which is more complex than the single parameter cases because conflicts can arise between three sources of information, namely the likelihood, the prior distribution for the location parameter and the prior for the scale parameter. We establish sufficient conditions on the distributions in a location–scale model to resolve conflicts in different ways as a single observation tends to infinity. In addition, for each case, we explicitly give the limiting posterior distributions as the conflict becomes more extreme.     

Transnational issue networks in real and virtual space: the case of women,peace and security

To what extent do online issue networks serve as a proxy for their real‐space counterparts in structure and substance? This question is significant because a number of scholars have begun to study transnational advocacy networks through their representations online. We explored whether this assumption is valid by comparing the network composition and agenda composition of the advocacy network around ‘women, peace and security’, as operationalized through a web‐based survey of actual activists, and the network's online representations of itself, as measured through advocacy websites. Two specific concerns drove the study. First, how closely does the structure of issue networks, as represented on the World Wide Web, correspond with actual advocates' understanding of the players within a specific issue domain? Second, to what extent does the online issue agenda correlate with the most prominent issues described by real‐space advocates within a transnational network? Our findings yielded a high correlation between the online issue agenda and activists’ interpretations of the agenda. However, we found that while hyperlink analysis is an effective tool for identifying the ‘hubs’ or ‘gatekeepers’ within a specific issue network, the nature of the World Wide Web makes it is a blunt tool with which to capture the broader network. This suggests that while the web poses important opportunities as a data source, scholars of transnational networks must pay closer attention to the methodological assumptions implicit in their reliance on this and other new media.