Statistical concepts of a priori and a posteriori risk classification in insurance

Everyday we face all kinds of risks, and insurance is in the business of providing us a means to transfer or share these risks, usually to eliminate or reduce the resulting financial burden, in exchange for a predetermined price or tariff. Actuaries are considered professional experts in the economic assessment of uncertain events, and equipped with many statistical tools for analytics, they help formulate a fair and reasonable tariff associated with these risks. An important part of the process of establishing fair insurance tariffs is risk classification, which involves the grouping of risks into various classes that share a homogeneous set of characteristics allowing the actuary to reasonably price discriminate. This article is a survey paper on the statistical tools for risk classification used in insurance. Because of recent availability of more complex data in the industry together with the technology to analyze these data, we additionally discuss modern techniques that have recently emerged in the statistics discipline and can be used for risk classification. While several of the illustrations discussed in the paper focus on general, or non-life, insurance, several of the principles we examine can be similarly applied to life insurance. Furthermore, we also distinguish between a priori and a posteriori ratemaking. The former is a process which forms the basis for ratemaking when a policyholder is new and insufficient information may be available. The latter process uses additional historical information about policyholder claims when this becomes available. In effect, the resulting a posteriori premium allows one to correct and adjust the previous a priori premium making the price discrimination even more fair and reasonable.     

Learning to play chess: How to make sense of a politics of representation with people in poverty

Despite the growing involvement of people in poverty in social policy, their participation does not necessarily take place on a par with policymakers, as the latter often do not really embrace their demands for social justice. It is, therefore, argued that social work has a role to play in the process of merging knowledge of people in poverty with that of policymakers and other stakeholders by representing their perspectives in public debate. By drawing on an in‐depth qualitative research of five “Associations where People in Poverty Raise their Voice” (Belgium), the complexity of the direct participation of people in poverty in such a politics of representation is analyzed, as well as the different roles social work practitioners can take on in dealing with this complexity. Here, two roles are distinguished: “a guardian of collective and transformative elements”; and “a strategical chess player.” We conclude that practitioners need to reflect critically on participatory premises and practices and consider whether these strategies actually contribute to societal change. However, the ideal of parity of participation entails that such strategic considerations should always be collaboratively discussed with people in poverty.     

Leadership as social identity management: Introducing the Identity Leadership Inventory (ILI) to assess and validate a four-dimensional model

Although nearly two decades of research have provided support for the social identity approach to leadership, most previous work has focused on leaders' identity prototypicality while neglecting the assessment of other equally important dimensions of social identity management. However, recent theoretical developments have argued that in order to mobilize and direct followers' energies, leaders need not only to ‘be one of us’ (identity prototypicality), but also to ‘do it for us’ (identity advancement), to ‘craft a sense of us’ (identity entrepreneurship), and to ‘embed a sense of us’ (identity impresarioship). In the present research we develop and validate an Identity Leadership Inventory (ILI) that assesses these dimensions in different contexts and with diverse samples from the US, China, and Belgium. Study 1 demonstrates that the scale has content validity such that the items meaningfully differentiate between the four dimensions. Studies 2, 3, and 4 provide evidence for the scale's construct validity (distinguishing between dimensions), discriminant validity (distinguishing identity leadership from authentic leadership, leaders' charisma, and perceived leader quality), and criterion validity (relating the ILI to key leadership outcomes). We conclude that by assessing multiple facets of leaders' social identity management the ILI has significant utility for both theory and practice.     

Toward a Refined Insight Into the Importance of Volunteers’ Motivations for Need-Based Experiences,Job Satisfaction,Work Effort,and Turnover Intentions in Nonprofit Sports Clubs: A Person-Centered Approach

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Extensive variable-centered research guided by Self-Determination Theory (SDT) has provided insights into...     

Multivariate mixtures of Erlangs for density estimation under censoring

Multivariate mixtures of Erlang distributions form a versatile, yet analytically tractable, class of distributions making them suitable for multivariate density estimation. We present a flexible and effective fitting procedure for multivariate mixtures of Erlangs, which iteratively uses the EM algorithm, by introducing a computationally efficient initialization and adjustment strategy for the shape parameter vectors. We furthermore extend the EM algorithm for multivariate mixtures of Erlangs to be able to deal with randomly censored and fixed truncated data. The effectiveness of the proposed algorithm is demonstrated on simulated as well as real data sets.     

Factors Associated with Return Migration of First-Generation Immigrants in Belgium (2001–2011)

Belgium is a country with a long and diverse history of migration. Given the diverse context of immigration to Belgium, reasons for return migration will most likely vary as well. With this study, we want to quantify the return migration of Belgium’s immigrants and assess whether socio-economic, sociodemographic and health factors are related to return migration. Individually linked census and register data comprising the total Belgian first-generation immigrant population aged 25+ were used. Age-standardized emigration rates (ASER) by migrant origin and gender were calculated for the period 2001–2011. Additionally, relative return migration differences were calculated by country of origin and gender, adjusted for age group, length of stay, household composition, socio-economic indicators (education, home ownership and employment status) and self-rated health in 2001. Return migration was most common among immigrants from Spanish descent and from the neighbouring countries and higher among men than among women. Return migration was highly selective in terms of older age, lower length of stay in Belgium, not living with a partner or children, being high-educated, unemployed and in good health. Key issues for future research include examining the reasons for return migration, identifying the country of destination and accounting for household characteristics.     

Pornography in small places and other spaces

This article investigates pornographic web-based media at a time when commercial pornography has flooded the Internet and pockets of sex activism are budding alongside the porn boom. Pornography moving freely across borders is foremost a capitalist vision, but the web’s sexual potency is equally defined by web users and artists who visit and maintain peer-to-peer networks for producing and sharing sexually explicit materials. Revisiting Foucault’s notion of space as ‘heterotopia’, networked sexual communication and pornography are shown to permeate physical places and other spaces. Web users cultivate attachments to everyday places and spaces other than the ones they routinely inhabit. Networked sexual agency materializes desire far beyond the confines of community rituals and commodity industries. Besides the fact that porn industries expand their markets and diversify products, sex communities emerge alongside these markets and play a vital role in negotiating sexuality. The article shows how the Internets decentralized mechanisms of power and communication, including debating societies and playgrounds, have entered the realm of online porn and sexuality. Developing a theoretical notion of space as other spaces, the article unfolds the sexual web as exuberant, dispersed in bodies and cultures, yet forcefully regulated by global corporations and nation-state governments.     

Economic hardship and depression across the life course: the impact of welfare state regimes

Previous research in the United States suggests that depression related to economic hardship decreases with age. We test whether this pattern can be generalized to other developed nations. Based on data from 23 countries in the European Social Survey (2006--2007), multilevel analyses show that the moderating role of age depends on the socio-political context. While the hardship--depression link is not significantly different across the life course in Nordic and Bismarckian regimes, the hardship--depression link increases with age in Southern and Eastern European countries and decreases with age in strength in Anglo-Saxon welfare states. Our findings suggest that welfare state regimes play a significant role in attenuating, boosting, or even reversing the health effects of social experiences such as economic hardship on aging. Health knowledge gained through research that ignores the socio-political context may be limited in terms of generalization.