Some new results on aggregate claim amounts from two heterogeneous Marshall–Olkin extended exponential portfolios

In this work, we discuss some stochastic comparisons of two aggregate claim amounts. Applications of our results to the value-at-risk and tail-value-at-risk are also mentioned. It is also shown that the aggregate claim amounts of risks exhibiting a weak form of dependence known as positive cumulative dependence (negatively associated) is larger (smaller) in convex order than the corresponding aggregate claim amounts under the theoretical independence assumption. The obtained results show that the correlations between individual risks increase stop-loss premiums corresponding to aggregate claim amounts. The results established here complete and extend the results of Barmalzan, Payandeh Najafabadi, and Balakrishnan (2017 Barmalzan, G., A. T. Payandeh Najafabadi, and N. Balakrishnan. 2017. Ordering results for aggregate claim amounts from two heterogeneous Marshall–Olkin extended exponential portfolios and their applications in insurance analysis. Theory of Probability and its Applications(to appear). [Google Scholar], Theory of Probability and its Applications, to appear).     

«Il n'y a pas d’avenir dans ce métier.» Être chauffeur de VTC en Afrique par temps de pandémie

Si les plateformes ont donné du travail à beaucoup d’Africains, les emplois créés sont de mauvaise qualité, comme la pandémie l'a bien montré. Dans ce contexte, les auteurs examinent la situation particulière des chauffeurs VTC en Afrique en s'appuyant sur des entretiens approfondis, réalisés au Kenya, et sur les méthodes de l'ethnographie virtuelle. Ils montrent que ces travailleurs ont recours à un «régime de débrouille», associant résilience, réajustement et résistance. Pour améliorer les conditions de travail et lutter contre la précarité dans le secteur, il faut à la fois que les pouvoirs publics instaurent des cadres réglementaires et que les travailleurs se mobilisent collectivement.     

Correlated equilibrium in a nutshell

We analyze the concept of correlated equilibrium in the framework of two-player two-strategy games. This simple framework makes it possible to clearly demonstrate the characteristic features of this concept. We develop an intuitive and easily memorizable test for equilibrium conditions and provide a complete classification of symmetric correlated equilibria in symmetric games.     

Family Change and Continuity in Iran: Birth Control Use Before First Pregnancy

Using data from the 2002 Iran Fertility Transition Survey, we examined birth control use between marriage and first pregnancy. We focused on the post‐1990 increase in birth control use and develop two explanations. The first posits that birth control use reflects a new marriage form, the conjugal marriage, which places a heightened value on the spousal relationship while deemphasizing the centrality of parenthood. A second explanation stresses the use of a new resource, effective birth control, within an Iranian‐Islamist view of marriage. Key to this explanation is the role of the state—Iranian political/religious actors encourage early marriage and the use of birth control. Although the explanations could be complementary, evidence provides more support for the latter.     

The Challenge of Agricultural Sustainability for Asia and Europe

It is expected that climate change (CC), growing population, increasing urbanization and improving living standards are amongst the major drivers influencing future agricultural development needs. Under conventional agricultural systems, the main sources of growth in crop production are well known. Beyond suffering its consequences, agriculture has been shown to act as a driver of CC, primarily through the production and release of about 15% of the atmospheric greenhouse gases but also by altering the resilience of the agro-ecosystems. The main criterion for the production systems called conservation agriculture (CA) is the provision of an optimum environment in the root-zone to maximum possible depth. Under CA the water-holding capacity of the soil increases, and water losses are reduced. CA combined with other complementary techniques can also help reduce the emissions for methane and nitrous oxides and at the same time it can improve rural and socio-economic development.     

Public Attitudes toward Abortion in Israel: A Research Note

Objective . For the first time since the mid-1970s, this study explored sociodemographic correlates of abortion attitudes among Israeli Jews and compared them with those reported by the General Social Survey in the United States. Methods . A survey in the representative sample of Jewish adults living in urban areas across Israel ( N = 546) that included two related items on the attitude toward abortion for nonvital reasons. Results . Using multiple regression, four statistically and socially significant correlates of antiabortion attitudes were identified: Greater religiosity (especially Ultra-Orthodox affiliation), lower than average income, greater number of children, and right-wing political preference. Gender and age did not emerge as significant correlates of abortion attitudes. Whereas American Jews form the mainstay of the prochoice camp, Jews in Israel are clearly divided along the lines of religiosity, ethnicity, socioeconomic status, and political views. Conclusions . In both Israel and the United States, the sociodemographic profiles of abortion supporters and opponents have been rather similar and stable over the last 25 years. This may point to the stable patterns of religiosity in both societies, since antiabortion sentiments have mainly been fueled by religious fundamentalism, regardless of formal denomination.     

Finite-Sample Properties of Some Alternative GMM Estimators

We investigate the small-sample properties of three alternative generalized method of moments (GMM) estimators of asset-pricing models. The estimators that we consider include ones in which the weighting matrix is iterated to convergence and ones in which the weighting matrix is changed with each choice of the parameters. Particular attention is devoted to assessing the performance of the asymptotic theory for making inferences based directly on the deterioration of GMM criterion functions.     

From Acute Palliation to Chronic Care: Using the Narratives of Two Gay Caregivers to Explore Experiences of Providing HIV Support Across Sociohistorical Contexts

Despite the longstanding shift in conceptualizing HIV/AIDS as a site of chronic care, versus one of acute palliation, few attempts have been made to examine caregiving in the context of this change. This study constitutes a preliminary attempt at exploring the evolving nature of HIV/AIDS caregiving among sexual minorities, primarily by comparing the narratives of two partnered caregivers of HIV-positive gay men whose stories are located in disparate sociohistorical contexts. Whereas one caregiver provided support during an era in which HIV/AIDS was primarily conceptualized as acutely life-limiting, the other did so in the contemporary period of chronic HIV care. Although similarities are noted across the stories, distinctions are also apparent in how the caregivers encounter expressions of homophobia and HIV stigma, and negotiate these realities distinctly as a function of sociohistorical context. In particular, despite the salience of these systemic barriers across the two narratives, these expressions of marginalization appear to occur more routinely and indefinitely in the context of chronic care. This article concludes with implications of the study's findings on theory, research, policy, and practice.