On Ehrhart polynomials and probability calculations in voting theory

In voting theory, analyzing the frequency of an event (e.g. a voting paradox), under some specific but widely used assumptions, is equivalent to computing the exact number of integer solutions in a system of linear constraints. Recently, some algorithms for computing this number have been proposed in social choice literature by Huang and Chua (Soc Choice Welfare 17:143–155 2000) and by Gehrlein (Soc Choice Welfare 19:503–512 2002; Rev Econ Des 9:317–336 2006). The purpose of this paper is threefold. Firstly, we want to do justice to Eugène Ehrhart, who, more than forty years ago, discovered the theoretical foundations of the above mentioned algorithms. Secondly, we present some efficient algorithms that have been recently developed by computer scientists, independently from voting theorists. Thirdly, we illustrate the use of these algorithms by providing some original results in voting theory. Helpful comments by Philippe Clauss and his team are gratefully acknowledged.     

Empirical Bayes estimates of finite mixture of negative binomial regression models and its application to highway safety

The empirical Bayes (EB) method is commonly used by transportation safety analysts for conducting different types of safety analyses, such as before–after studies and hotspot analyses. To date, most implementations of the EB method have been applied using a negative binomial (NB) model, as it can easily accommodate the overdispersion commonly observed in crash data. Recent studies have shown that a generalized finite mixture of NB models with K mixture components (GFMNB-K) can also be used to model crash data subjected to overdispersion and generally offers better statistical performance than the traditional NB model. So far, nobody has developed how the EB method could be used with finite mixtures of NB models. The main objective of this study is therefore to use a GFMNB-K model in the calculation of EB estimates. Specifically, GFMNB-K models with varying weight parameters are developed to analyze crash data from Indiana and Texas. The main finding shows that the rankings produced by the NB and GFMNB-2 models for hotspot identification are often quite different, and this was especially noticeable with the Texas dataset. Finally, a simulation study designed to examine which model formulation can better identify the hotspot is recommended as our future research.     

The Effect of Imputation Procedures on First Birth Intervals: Evidence from Five African Fertility Surveys

In most African societies there is little motivation to remember dates of demographic events with the level of precision required in demographic surveys. Consequently it is common that the large majority of survey respondents can provide only the calendar year of occurrence or their age at the time of the event. The World Fertility Survey Group decided to handle the problem of poor date reporting by using a computer program to impute the missing information. This article illustrates the effect of these imputation procedures on cross-national differentials in the proportion of premarital first births in Benin, Cameroon, Cote d’Ivoire, Ghana, and Nigeria. The analysis demonstrates that the exceptionally low proportion of premarital first births in Ghana is an artifact of the imputation procedures.     

Preparing adolescents for adulthood

Pregnancy-related school dropouts have become a matter of public concern throughout sub-Saharan Africa. In most cases, schoolgirls who become pregnant either have to resort to unsafe illegal abortions, or they face official school expulsion. Because girls who drop out of school due to pregnancy usually do not return to school to complete their education after the birth of their child, their opportunities for socioeconomic advancement are limited. Many African governments have included family life education programs in the school curriculum in an attempt to educate adolescents about the consequences and responsibilities associated with sexual activity. The high rates of schoolgirl pregnancies suggest that these programs have their shortcomings, and indicate that educational policies should attempt not only to reduce the incidence of schoolgirl pregnancies, but also to assist pregnant schoolgirls to complete their education. In this paper, we use data from a sample of 154 Kenyan primary and secondary schools to study differentials in the extent to which various types of schools are affected by pregnancy-related school dropouts, and to examine the opinions of the head teachers regarding teaching about contraceptive methods and readmittance of pregnancy-related dropouts.     

Children's appraisals as mediators of the relationship between domestic violence and child adjustment

This study examines the relationships among variables that were likely to mediate the effects of exposure to domestic violence on children's internalizing problems (i.e., children's appraisals of domestic violence and their perceptions of family relationships). The study was conducted with 79 children exposed to domestic violence, including 41 boys and 38 girls, aged between 9 and 12 years old. Indicators used for children's appraisals of violence were attribution of blame and perceived threat. Children's perceptions of family relationships were based on their levels of parentification and the degree of their loyalty conflicts. A path analysis was used to verify the predictive model's pathways and to test the multiple mediator effects. Findings confirm the contribution of mediating variables and also reflect the association between self-blame and children's parentification. The results stress the relevance of evaluating the combined role of different potential mediators to provide a better understanding of the impact of domestic violence on children.     

从法国穆斯林移民的生存现状透视法国的移民模式

法国季节性人口迁移由来已久,且迁移的地域遍及欧洲。欧洲国家对人口迁徙情况进行清查和评估始于1805年法兰西第一帝国时期,当时实行以“血统主义”为原则的国籍制度,其用意在于保证拿破仑军队充足的兵源,这与后来共和政体实行的“属地主义”原则相对立。21世纪初,移民问题成为法国对内政策面临的一大挑战,它与公共安全、国民身份认同、就业市场、欧盟公共事务政策的制订以及在第二代移民中实现法国模式的“共和”与“非宗教化”的融合等重大问题息息相关。欧洲国家之间与欧洲国家之外的人口迁移5I发以下问题：欧洲居民的原国籍问题、法国国籍问题、法国公民权的行使问题以及在重组后的家庭种族构成愈加复杂的条件下个人身份的构建问题等。     

Potential and probable pathological gamblers: Where do the differences lie?

A large proportion of adolescents engage in gambling activities and the prevalence of pathological gambling is high. This study presents a factor analysis of responses from 122 college students who obtained a score of 3 or greater on the South Oaks Gambling Screen (SOGS), the most widely used instrument to identify probable and potential pathological gamblers. The analysis showed five dimensions: Illegal Behaviors, Heavy Gambling, Eating Disorders, Parentally Modelled/Less Impulsive, and Worry. Analyses revealed that except for the Eating Disorders factor, all factors clearly differentiated the probable from potential pathological gamblers, as identified by the SOGS. Results raise important questions about the relationship of pathological gambling to other psychopathological or antisocial behaviors. Thus the probable pathological gambler category represents a wide-ranging behavioral profile that goes beyond gambling per se. Avenues for future research as well as clinical implications are discussed.This research was partially supported by grants from Le Fonds Richelieu, le Conseil Québécois de la Recherche Sociale and the Social Sciences and Humanities Research Council of Canada.     

The Endowment Effect,Status Quo Bias and Loss Aversion: Rational Alternative Explanation

The endowment effect, status quo bias, and loss aversion are robust and well documented results from experimental psychology. They introduce a wedge between the prices at which one is willing to sell or buy a good. The objective of this paper is to address this wedge. We show that the presence of asymmetric information in a rational-agent framework can also account for the endowment effect, status quo bias and loss aversion without invoking psychology-based explanations proposed in the past.