Transnational Twist: Pecuniary Remittances and the Socioeconomic Integration of Authorized and Unauthorized Mexican Immigrants in Los Angeles County1

Annual U.S.‐Mexico pecuniary remittances are estimated to have more than doubled recently to at least $10 billion ‐ augmenting interest among policymakers, financial institutions, and transnational migrant communities concerning how relatively poor expatriate Mexicans sustain such large transfers and the impact on immigrant integration in the United States. We employ the 2001 Los Angeles County Mexican Immigrant Residency Status Survey (LAC‐MIRSS) to investigate how individual characteristics and social capital traditionally associated with integration, neighborhood context, and various investments in the United States influenced remitting in 2000. Remitting is estimated to have been inversely related to conventional integration metrics and influenced by community context in both sending and receiving areas. Contrary to straight‐line assimilation theories and more consistent with a transnational or nonlinear perspective, however, remittances are also estimated to have been positively related to immigrant homeownership in Los Angeles County and negatively associated with having had public health insurance such as Medicaid.     

Foundational Issues in Risk Assessment and Risk Management

This is a perspective article on foundational issues in risk assessment and management. The aim is to discuss the needs, obstacles, and challenges for the establishment of a renewed, strong scientific foundation for risk assessment and risk management suited for the current and future technological challenges. The focus is on (i) reviewing and discussing the present situation and (ii) identifying how to best proceed in the future, to develop the risk discipline in the directions needed. The article provides some reflections on the interpretation and understanding of the concept of “foundations of risk assessment and risk management” and the challenges therein. One main recommendation is that different arenas and moments for discussion are needed to specifically address foundational issues in a way that embraces the many disciplinary communities involved (from social scientists to engineers, from behavioral scientists to statisticians, from health physicists to lawyers, etc.). One such opportunity is sought in the constitution of a novel specialty group of the Society of Risk Analysis.     

The Quality of Recent Pacific Sociological Association (PSA) Meetings: Location,Session Quality and Institutional Change

Employing data (n?=?734) collected from those having attended the Pacific Sociological Association (PSA) annual meetings held in San Diego, California (2012) and Reno, Nevada (2013), we test whether session quality and host-city satisfaction are positively associated with how respondents rated the overall quality of the meetings. A majority (54 %) of respondents reported the quality of the meetings highly (“Above Average” or “Excellent”), and suggestive of the importance of conference location, this declined from 64 % in 2012 to 41 % in 2013. Controlling for individual characteristics and institutional affiliation, regression results intimate that both host-city satisfaction and session quality are positively associated with how respondents rated the overall quality of the meetings. And they suggest that the former is somewhat more important than the latter for explaining variation in meeting quality. A final stage of our analysis (n?=?205) finds that attendees’ evaluations of changes in how the 2013 PSA meetings were developed and organized are positively associated with meeting quality without diminishing the independent effects of session or location quality. We discuss implications of these results for future PSA meetings, as well as for research investigating how to improve the quality of regional academic conferences more generally.     

Degradation data analysis for samples under unequal operating conditions: a case study on train wheels

Traditionally, reliability assessment of devices has been based on life tests (LTs) or accelerated life tests (ALTs). However, these approaches are not practical for high-reliability devices which are not likely to fail in experiments of reasonable length. For these devices, LTs or ALTs will end up with a high censoring rate compromising the traditional estimation methods. An alternative approach is to monitor the devices for a period of time and assess their reliability from the changes in performance (degradation) observed during the experiment. In this paper, we present a model to evaluate the problem of train wheel degradation, which is related to the failure modes of train derailments. We first identify the most significant working conditions affecting the wheel wear using a nonlinear mixed-effects (NLME) model where the log-rate of wear is a linear function of some working conditions such as side, truck and axle positions. Next, we estimate the failure time distribution by working condition analytically. Point and interval estimates of reliability figures by working condition are also obtained. We compare the results of the analysis via an NLME to the ones obtained by an approximate degradation analysis.     

A Comparison Between Probabilistic and Dempster‐Shafer Theory Approaches to Model Uncertainty Analysis in the Performance Assessment of Radioactive Waste Repositories

Model uncertainty is a primary source of uncertainty in the assessment of the performance of repositories for the disposal of nuclear wastes, due to the complexity of the system and the large spatial and temporal scales involved. This work considers multiple assumptions on the system behavior and corresponding alternative plausible modeling hypotheses. To characterize the uncertainty in the correctness of the different hypotheses, the opinions of different experts are treated probabilistically or, in alternative, by the belief and plausibility functions of the Dempster‐Shafer theory. A comparison is made with reference to a flow model for the evaluation of the hydraulic head distributions present at a radioactive waste repository site. Three experts are assumed available for the evaluation of the uncertainties associated with the hydrogeological properties of the repository and the groundwater flow mechanisms.     

On the superposition of overlapping Poisson processes and nonparametric estimation of their intensity function

It is shown that, when measuring time in the Total Time on Test scale, the superposition of overlapping realizations of a nonhomogeneous Poisson process is also a Poisson process and is sufficient for inferential purposes. Hence, many nonparametric procedures which are available when only one realization is observed can be easily extended for the overlapping realizations setup. These include, for instance, the constrained maximum likelihood estimator of a monotonic intensity and bootstrap confidence bands based on Kernel estimates of the intensity. The kernel estimate proposed here performs the smoothing in the Total Time on Test scale and it is shown to behave approximately as a usual kernel estimate but with a variable bandwidth which is inversely proportional to the number of realizations at-risk. Likewise, bootstrap samples can be obtained from the single realization of the superimposed process. The methods are illustrated using a real data set consisting of the failure histories of 40 electrical power transformers.     

Practical modeling strategies for unbalanced longitudinal data analysis

In practice, data are often measured repeatedly on the same individual at several points in time. Main interest often relies in characterizing the way the response changes in time, and the predictors of that change. Marginal, mixed and transition are frequently considered to be the main models for continuous longitudinal data analysis. These approaches are proposed primarily for balanced longitudinal design. However, in clinic studies, data are usually not balanced and some restrictions are necessary in order to use these models. This paper was motivated by a data set related to longitudinal height measurements in children of HIV-infected mothers that was recorded at the university hospital of the Federal University in Minas Gerais, Brazil. This data set is severely unbalanced. The goal of this paper is to assess the application of continuous longitudinal models for the analysis of unbalanced data set.     

Choosing between alternative classification criteria to measure the labour force state

Summary.  Labour force counting relies on general guidelines that are set by the International Labour Office to classify individuals into three labour force states: employment, unemployment and inactivity. However, the resulting statistics are known to be sensitive to slight variations in operational definitions which are prima facie consistent with the general guidelines. We consider two interpretations of the general guidelines, operationalized by the criterion that is currently followed by Eurostat and a criterion that was followed by the Italian Statistical Office up to 1992. After showing that the labour force statistics resulting from the two criteria differ considerably, we compare individuals whose classification depends on the criterion that is adopted with individuals whose classification is common between criteria to study the boundary between unemployment and inactivity. An application of our strategy is presented using data from the Italian Labour Force Survey, painting a picture neatly against the criterion that is currently followed by Eurostat.     

Cross‐border commuters: How to segment Them? A Framework of Analysis

The removal of barriers to labour mobility and the enhancement of cross‐border mobility are expected to reduce regional disparities by contributing to a more efficient allocation of labour. For some time now, however, researchers have considered borders and cross‐border regions to be marginal zones. Therefore, we contribute to the discussion by providing a qualitative framework for the segmentation of the cross‐border job market, capable of addressing some questions relevant to the management of cross‐border commuting regarding the nature of imbalances that characterize the cross‐border job market and the main factors underpinning the phenomenon. To do so, we focused specifically on the Euroregion “Regio Insubrica”, a cross‐boundary cooperation community between Italy and Switzerland. Nevertheless, the proposed framework may be easily applied to all the existing cross‐border regions across the world in order to help explain the imbalances that exist, and support decision‐makers regarding educational and labour market policies.     

Der Einfluss von Mehrfachmandatstr?gern auf die Unternehmensperformance

Although interlocking directorates are regularly associated with a negative connotation, empirical evidence is as yet insufficient to offer convincing answers about their impact on performance. Contradicting results can mostly be explained both by the use of different theoretical frameworks and value creation measures. In order to shed more light as to what effect busy directors have on shareholder??s wealth, we have developed a two-pillar model explaining the potential contributions of directorship interlocks to value creation within an enlarged corporate governance perspective. The validity of the model has been tested through a panel data analysis of director networks within German Blue Chip corporations over a 5 year period from 2001 to 2005. Empirical tests indicate that the performance effects of interlocks depend on the nature of the board positions occupied. Moreover, statistical modelling confirms the existence of cognitive contributions of interlocked directors and partially shows positive effects on value creation. Finally the study argues in favour of board composition without external executive directors and suggests that a simple reduction of the number of external board positions legally authorized, does not within itself enhance corporate performance.