Hostage taking: Understanding terrorism event dynamics

This paper employs advanced time series methods to identify the dynamic properties of three hostage taking series. The immediate and long run multipliers of three covariates—successful past negotiations, violent ends, and deaths—are identified. Each hostage series responds differently to the covariates. Past concessions have the strongest impact on generating future kidnapping events, supporting the conventional wisdom to abide by a stated no-concession policy. Each hostage series has different changepoints caused by a variety of circumstances. Skyjackings and kidnappings are negatively correlated, while skyjackings and other hostage events are positively correlated. Policy recommendations are offered.     

The Middle‐class in the German Welfare State: Beneficial Involvement at Stake?

The working‐class is typically regarded as the driving force of welfare state development. Yet, some argue that the middle‐classes' beneficial involvement in the welfare state is crucial for its financial sustainability and popular legitimacy. Against this backdrop, we investigate how recent welfare state reforms in Germany which affect the status of the middle‐class are viewed and discussed by this group. Germany is a particularly interesting case because its welfare state is seen to be centred on the desires of the middle‐class, especially through its focus on status maintenance and horizontal redistribution over the life‐course. However, the move from status maintenance to minimum income support in unemployment provision and the strengthening of private old age provision challenge this assumption. Thus, we ask how the German middle‐class views the emerging abandonment of the principle of status maintenance and the shift from collective to individual responsibility. Based on qualitative material from focus groups, we find that individual responsibility is generally supported, but that the state is still assigned responsibility for providing basic levels of social security. Furthermore, for those groups seen as less capable of acting individually responsible (e.g. the poor or long‐term unemployed) the ‘inducement’ of – or assistance for – individually responsible behaviour by the state is demanded. Overall, while the principle of ‘individual responsibility’ seems to find some resonance among the middle‐class members interviewed, they still try to balance individual and collective responsibility.     

Determining Sample Size Using Fast and Slow Thinking

ABSTRACT

Using SPSS's bootstrapping procedures, this article demonstrates an approach to determining sample size that combines fast (heuristics or rules-of-thumb) and slow (statistical power analysis) thinking to balance statistical power, precision, and practicality. Sample size is determined for six commonly used statistical procedures: independent groups t-test, one-way ANOVA, one-way MANOVA, Pearson's r correlation, linear regression, and logistic regression. Overall, findings suggest that both approaches may under or over-estimate sample size. Both approaches yielded similar parameter and confidence interval estimates, but varied, sometimes by a factor of two, in their sample size requirements. It is hoped that this study's procedure and results will provide beginning reference points for sample size determination, and encourage researchers continue to search for resolutions for often difficult sample-size decisions.     

Foreign-born health integration during the transition to adulthood: The case of weight

Nativity differences in youths’ health in the United States are striking—the children of foreign-born parents often have healthier outcomes than those of native-born parents. However, very little is known about how immigrant-native differences evolve within the same individuals over time, or about life cycle aspects of the health-related integration of youth with migration backgrounds. Using data from the National Longitudinal Study of Adolescent Health, I examine nativity differences in trajectories of weight gain during adolescence and early adulthood, as well as the degree to which temporal patterns are stratified by race/ethnicity and socioeconomic status. I examine whether nativity differences converge, diverge or remain stable over time, and whether patterns are socially stratified within and across nativity groups. I find that first-generation adolescents begin at a lower weight than their third generation peers and gain weight at a significantly slower pace, resulting in meaningful differences by early adulthood. More complex examination of the relationship between nativity and weight gain reveals additional differences by ethnicity: the foreign-born advantage over time does not extend as strongly to Hispanic adolescents. The findings demonstrate how the health-related integration of foreign-born youth is tied to race/ethnicity and socioeconomic circumstances, and suggest the need to examine the ways in which social circumstances and health change together.     

Should I Stay or Should I Go? Explaining Turnover Intentions with Organizational Identification and Job Satisfaction*

The social identity approach is a powerful theoretical framework for the understanding of individuals' behaviour. The main argument is that individuals think and act on behalf of the group they belong to because this group membership adds to their social identity, which partly determines one's self‐esteem. In the organizational world, social identity and self‐categorization theories state that a strong organizational identification is associated with low turnover intentions. Because identification is the more general perception of shared fate between employee and organization, we propose that the relationship between identification and turnover will be mediated by job satisfaction as the more specific evaluation of one's task and working conditions. In four samples we found organizational identification feeding into job satisfaction, which in turn predicts turnover intentions.     

On edge orienting methods for graph coloring

We consider the problem of orienting the edges of a graph so that the length of a longest path in the resulting digraph is minimum. As shown by Gallai, Roy and Vitaver, this edge orienting problem is equivalent to finding the chromatic number of a graph. We study various properties of edge orienting methods in the context of local search for graph coloring. We then exploit these properties to derive four tabu search algorithms, each based on a different neighborhood. We compare these algorithms numerically to determine which are the most promising and to give potential research directions.     

Value drivers of social businesses: A business model perspective

Hybrid organizational forms that combine commercial and welfare institutional logics play an increasingly important role in addressing the grand societal challenges we face today. Building on the literatures on hybrid organizations and social business models, we explore the characteristics of social businesses from a business model perspective. This study seeks to better understand the particularities and value drivers of hybrid social purpose in contrast to purely commercial business models. We follow a grounded theory approach and our findings are based on interview data from 17 social business firms. Building on social businesses' identified particularities, we propose four value drivers of social business models: 1) responsible efficiency, 2) impact complementarities, 3) shared values, and 4) integration novelties. We link our findings to the literature, contributing new insights into social businesses models and implications for practitioners.     

Wisdom of the crowd and capabilities of a few: internal success factors of crowdsourcing for innovation

Crowdsourcing has been demonstrated to be an effective strategy to enhance the efficiency of a firm’s innovation process. In this paper, we focus on tournament-based crowdsourcing (also referred to as “broadcast search”), a method to solve technical problems in form of an open call for solutions to a large network of experts. Based on a longitudinal study of six companies piloting this application of crowdsourcing, we identify barriers and sources of resistance that hinder its implementation in firms. Our paper contributes to the state of research by analyzing crowdsourcing on the level of pilot projects, hence providing a workflow perspective that considers the creation of dedicated processes and operations of crowdsourcing. This project level analysis enables the identification of specific challenges managers face when implementing crowdsourcing within an established R&D organization. Following a design science approach, we derive suggestions for organizational interventions to overcome these barriers. We find that dedicated promoter roles strongly contribute to a successful implementation of crowdsourcing, turning pilot projects into an organizational routine.