Dependent Insurance Risk Model: Deterministic Threshold

This article considers a dependent insurance risk model. We assume that the inter-arrival time depends on the previous claim size through a deterministic threshold structure. Adjustment coefficient and Lundberg-type upper bound for the ruin probability are obtained. In case of exponential claim size, an explicit solution for the ruin probability is obtained by solving a system of ordinary delay differential equations. Some numerical results are included for illustration purposes.     

Social movement schools: sites for consciousness transformation,training, and prefigurative social development

ABSTRACT

We develop the concept of “social movement school’ (SMS), showing how these organizational spaces are deliberately designed for purposes of educating, mentoring, training, and coordinating individuals as effective, committed movement agents. SMSs can also be important sites of prefigurative design and practice for future societal development consistent with movement goals. We motivate the theoretical significance of SMSs based on five perspectives in social movement scholarship: (1) resource mobilization; (2) cultural approaches to repertoires of contention; (3) cognitive perspective; (4) micro-mobilization; and (5) biographical consequences of participation. We then offer a typology to capture primary purposes, and spatial reach within the broad field of SMSs. Within-movement variation is illustrated by focusing on a variety of SMSs in the U.S. civil rights movement; and the cross-movement breadth of the concept is illustrated by highlighting contemporary SMS forms drawn from three very different movements–labor, radical feminism, and mindfulness meditation movements. In the interest of launching a research agenda on SMSs, we end with several key questions that could serve to guide future research. Important theoretical, empirical, and practical considerations suggest that SMSs deserve the attention of scholars and activists alike.     

Optimal Randomized Scheduling by Replacement

In the replacement scheduling problem, a system consists of n processors drawn from a pool of p,all initially alive. At any time some processor can die. The scheduler is immediately informed of the fault butnot of its location. It must then choose another set of n processors. If this new set contains a dead processor, the system crashes and halts. The performance of a scheduling protocol is measured by the expected number of deaths the system tolerates before it crashes. We provide an optimal randomized scheduling protocol for this problem.The framework of this work combines an absolute performance measure for protocols and so-called adaptive online adversaries. This framework is rarely addressed because of the complexity of the interaction between protocols and adversaries. A major contribution of ourwork is to provide a theoretical foundation for the analysis of this interaction. In particular we make explicit how the protocol and the adversary affect the probability distribution of the analysis—a very general problem. We carefully analyze the exchange of sinformation between the two players, and reveal how they use their information optimally. The optimality of the protocol is established by using of a saddle point method for protocols and adversaries.     

An Exploratory Study of Trust and Material Hardship in Ghana

We explore associations among interpersonal (thick and thin) and institutional (legislative, executive, and judicial) trust and material hardship outcomes in Ghana. We use data from the 2008 Afrobarometer survey. Material hardship is conceptualized in terms of frequency of going without five basic necessities/consumptive deprivations, each of which a separate outcome (food, water, medical care, cooking fuel, and cash income). Five multinomial logistic regression models are estimated. Models also include relevant socioeconomic and cultural factors. The stepwise forward entry method was used to identify important variables for each model, and common and unique predictors of each outcome are discussed. Results suggest that deprivations are trust-specific in Ghana. Interpersonal and institutional trust types matter differentially (for example, trust in parliament/national assembly is a unique food deprivation predictor; trust in courts is a unique water deprivation predictor; and trust in police is a unique cash income deprivation predictor). Common trust predictors across models are thin trust (trust in other Ghanaians) for predicting food and cooking fuel infrequency outcomes and executive trust for predicting water, medical care, and cash income infrequency outcomes. Some of the non-trust variables, like education and ethnicity, were prominent predictors of deprivation outcomes across all models. This is one of the beginning studies to explore micro-level data in an important area of trust and material hardship in Sub-Saharan Africa. The study also attempts to conceptualize material hardship within the context of a developing country and provides insightful results that could be beneficial to other research investigators and further probed in future studies building on this work. The study draws important implications for intervention policies based on analyses of material hardship composite parts which provide insights with great detail into specific target groups on specific component-outcomes.     

CALL FOR PAPERS

In this article historical patterns and recent trends in black migration in the United States are examined. The purpose of the article is two‐fold: (1) to examine historical changes in the volume and rates of migration between the southern region and nonsouthern regions; and (2) to determine the relative impact of migration types on the South's changeover to net in‐migration during the 1975–1980 migration interval.

The findings of this study indicate that the reversal of the historical pattern of net out‐migration of blacks from the southern region occurred two decades after the turnaround for the general population. The southern region changed from sizable net out‐migration for blacks during the period before 1970 to net in‐migration during the 1975–1980 migration interval. The changeover was due to a substantial decrease in the number of both southern‐born and non‐southern‐born blacks leaving the South. There were also increases in the rate of in‐migration into the region among both return migrants and nonsouthern migrants. The single most important factor influencing the turnaround was a decrease in the number of southern‐born blacks migrating out of the region. This finding is contrary to much current speculation about the role of return migrants in influencing the South's changeover to net in‐migration for the black population.     

European migration potential and prospects

Since the end of the war much discussion has taken place on the problem of emigration overseas. In this paper the author examines the potential number of emigrants from different parts of Europe, as well as the obstacles to emigration and immigration which they would have to overcome in order to realize their ambition. The general conclusion is reached that a resumption of migration on the nineteenth-century scale is extremely unlikely and that many of the public statements that have recently been made on the subject do not take full account of the facts.     

Racial differences in infant mortality by cause of death: The impact of birth weight and maternal age

This research examines racial disparities in infant mortality, overall and separately according to cause of death. Using linked birth and death records for the 1975 cohort of live births in Florida, racial differences are initially described and then explained statistically as a product of the distribution of births by birth weight and maternal age. The impact of birth weight is more pronounced than is the effect of maternal age. The analysis suggests the potential utility of examining infant mortality separately by cause of death. Based on the findings, we argue for systematic research focused on factors affecting birth weight.