Zero-inflated sum of Conway-Maxwell-Poissons (ZISCMP) regression

While excess zeros are often thought to cause data over-dispersion (i.e. when the variance exceeds the mean), this implication is not absolute. One should instead consider a flexible class of distributions that can address data dispersion along with excess zeros. This work develops a zero-inflated sum-of-Conway-Maxwell-Poissons (ZISCMP) regression as a flexible analysis tool to model count data that express significant data dispersion and contain excess zeros. This class of models contains several special case zero-inflated regressions, including zero-inflated Poisson (ZIP), zero-inflated negative binomial (ZINB), zero-inflated binomial (ZIB), and the zero-inflated Conway-Maxwell-Poisson (ZICMP). Through simulated and real data examples, we demonstrate class flexibility and usefulness. We further utilize it to analyze shark species data from Australia's Great Barrier Reef to assess the environmental impact of human action on the number of various species of sharks.     

Graphical representation of survival curves in the presence of time-dependent categorical covariates with application to liver transplantation

Graphical representation of survival curves is often used to illustrate associations between exposures and time-to-event outcomes. However, when exposures are time-dependent, calculation of survival probabilities is not straightforward. Our aim was to develop a method to estimate time-dependent survival probabilities and represent them graphically. Cox models with time-dependent indicators to represent state changes were fitted, and survival probabilities were plotted using pre-specified times of state changes. Time-varying hazard ratios for the state change were also explored. The method was applied to data from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Survival curves showing a ‘split’ at a pre-specified time t allow for the qualitative comparison of survival probabilities between patients with similar baseline covariates who do and do not experience a state change at time t. Time since state change interactions can be visually represented to reflect changing hazard ratios over time. A2ALL study results showed differences in survival probabilities among those who did not receive a transplant, received a living donor transplant, and received a deceased donor transplant. These graphical representations of survival curves with time-dependent indicators improve upon previous methods and allow for clinically meaningful interpretation.     

When women veterans return: The role of postsecondary education in transition in their civilian lives

Objective: The purpose of this study was to assess the current state of postsecondary educational settings’ outreach to military women who become students postservice. Participants: Data for the present cross-sectional study were obtained from the American College Health Association’s (ACHA) 2011–2014 National College Health Assessment II (NCHA). Methods: Demographic characteristics of the study sample were explored by calculating frequencies and percentages by military service status. Research questions were explored with Fisher’s exact test, maximum likelihood multiple logistic regression, as appropriate. Results: Women service member and veteran students received health information from their university/college less often than women students with no military experience on the following topics: alcohol and other drug use, depression and anxiety, sexual assault and relationship violence prevention, and stress reduction. Conclusions: The findings of this research identified clear gaps in service provision for women student veterans on college campuses and provided some possible models for intervention development.     

Protecting and Benchmarking Migrants’ Rights: An Analysis of the Global Compact for Safe,Orderly and Regular Migration

The Global Compact for Safe, Orderly, and Regular Migration (GCM) was to be “guided by human rights law and standards” in recognition of the rights of international migrants, who are currently protected by an overlapping patchwork of treaties and international law. The GCM contains many laudable commitments that, if implemented, will ensure that states more consistently respect, protect, and fulfil the rights of all migrants and also that states incorporate data on migration into a more cohesive governance regime that does more to promote cooperation on the issue of international migration. However, many concerns remain. Using a legal analysis and cross‐national policy data, we find that the GCM neither fully articulates existing law nor makes use of international consensus to expand the rights of migrants. In its first section, this article provides a concise analysis of the GCM's compliance with a set of core principles of existing international human rights law regarding migrants. In the second section, we apply a novel instrument to create an objective, cross‐national accounting of the laws protecting migrants’ rights in various national legal frameworks. Focusing on a sample of five diverse destination and sending countries, the results suggest we are close to an international consensus on the protection of a core set of migrants’ rights. This analysis should help prioritize the work necessary to implement the GCM.     

A port in a storm: Spontaneous volunteering and grassroots movements in Amsterdam. A resilient approach to the (European) refugee crisis

This article seeks to expand knowledge about spontaneous volunteering in Amsterdam during the European refugee crisis in the winter of 2015–16. As formal institutions, which relied on a top–down command and control approach, were unable to handle the relatively large number of refugees who arrived in a short period of time, grassroots social movements based on bottom–up participation emerged. Grassroots volunteers were not only politically engaged, protesting against the strict refugee reception policy, but they also became involved in the crisis response, showing a great deal of flexibility. Although the social movements struggled with their organizational structures, they were able to adapt their missions and structures to changing circumstances. To achieve a resilience‐based response to future refugee influxes, this article advocates for formal response organizations to dismantle their static, top–down approach, and for social movements to find a balance between participation and professionalism. If institutionalized refugee response organizations adapt to the dynamics of local conditions, they could create the conditions for resilient solutions in the crisis context.     

Entrenchment in publicly traded family firms: Evidence from the S&P 500

Family involvement in corporate governance through ownership, management, and board membership presents a unique dilemma for understanding the strategic impetus and costs of entrenchment decisions. The presence of shared family ties and the family-centered goals of firm principals call to question the applicability of extant agency arguments regarding the nature and antecedents of managerial entrenchment. Exploring this, we develop and test a model of family firm-specific determinants (i.e., family ownership and family's involvement in management and governance) of entrenchment in publicly traded firms by drawing upon principal-principal agency theory. Findings of the empirical analysis of family owned S&P 500 firms suggest family firms are motivated to entrench managers when doing so supports the pursuit of family-centric goals. However, the extent to which entrenchment supports such goals varies at different levels of family ownership.     

Cross Validation of the Gambling Problem Severity Subscale of the Canadian Adolescent Gambling Index (CAGI/GPSS) on a Sample of Ontario High School Students

This paper reports on the cross validation of the Gambling Problem Severity Subscale of the Canadian Adolescent Gambling Index (CAGI/GPSS). The CAGI/GPSS was included in a large school based drug use and health survey conducted in 2015. Data from students in grades 9–12 (ages 13–20 years) derived from the (N = 3369 students). The CAGI/GPSS produced an alpha of 0.789. A principle component analysis revealed two eigenvalues greater than one. An oblique rotation revealed these components to represent consequences and over involvement. The CAGI/GPSS indicated that 1% of the students fell into the “red” category indicating a severe problem and an additional 3.3% scored in the “yellow” category indicating low to moderate problems. The CAGI/GPSS was shown to be significantly correlated with gambling frequency (r = 0.36), largest expenditure (r = 0.37), sex (more likely to be male) (r = ?0.19), lower school marks (r = ?0.07), hazardous drinking, (r = 0.16), problem video game play (r = 0.16), as well as substance abuse. The CAGI/GPSS was cross validated using a shorted version of the short SOGS, r = 0.48. In addition the CAGI/GPSS and short SOGS produced very similar patterns of correlations results. The results support the validity and reliability of the CAGI/GPSS as a measure of gambling problems among adolescents.