Exploring variation in active network size: Constraints and ego characteristics

Studies of active personal networks have primarily focused on providing reliable estimates of the size of the network. In this study, we examine how compositional properties of the network and ego characteristics are related to variation in network size. There was a negative relationship between mean emotional closeness and network size, for both related and unrelated networks. Further, there was a distinct upper bound on total network size. These results suggest that there are constraints both on the absolute number of individuals that ego can maintain in the network, and also on the emotional intensity of the relationships that ego can maintain with those individuals.     

Games of capacity allocation in many-to-one matching with an aftermarket

In this paper, we study many-to-one matching (hospital–intern markets) with an aftermarket. We first show that every stable matching system is manipulable via aftermarket. We then analyze the Nash equilibria of capacity allocation games, in which preferences of hospitals and interns are common knowledge and every hospital determines a quota for the regular market given its total capacity for the two matching periods. Under the intern-optimal stable matching system, we show that a pure-strategy Nash equilibrium may not exist. Common preferences for hospitals ensure the existence of equilibrium in weakly dominant strategies whereas unlike in games of capacity manipulation strong monotonicity of population is not a sufficient restriction on preferences to avoid the non-existence problem. Besides, in games of capacity allocation, it is not true either that every hospital weakly prefers a mixed-strategy Nash equilibrium to any larger regular market quota profiles.     

Evaluating Efficiency-Equality Tradeoffs for Mobile Source Control Strategies in an Urban Area

In environmental risk management, there are often interests in maximizing public health benefits (efficiency) and addressing inequality in the distribution of health outcomes. However, both dimensions are not generally considered within a single analytical framework. In this study, we estimate both total population health benefits and changes in quantitative indicators of health inequality for a number of alternative spatial distributions of diesel particulate filter retrofits across half of an urban bus fleet in Boston, Massachusetts. We focus on the impact of emissions controls on primary fine particulate matter (PM_2.5) emissions, modeling the effect on PM_2.5 concentrations and premature mortality. Given spatial heterogeneity in baseline mortality rates, we apply the Atkinson index and other inequality indicators to quantify changes in the distribution of mortality risk. Across the different spatial distributions of control strategies, the public health benefits varied by more than a factor of two, related to factors such as mileage driven per day, population density near roadways, and baseline mortality rates in exposed populations. Changes in health inequality indicators varied across control strategies, with the subset of optimal strategies considering both efficiency and equality generally robust across different parametric assumptions and inequality indicators. Our analysis demonstrates the viability of formal analytical approaches to jointly address both efficiency and equality in risk assessment, providing a tool for decisionmakers who wish to consider both issues.     

History matters: The impact of reviews and sales of earlier versions of a product on consumer and expert reviews of new editions

Product reviews are assumed to be based on the observable characteristics of the underlying product. However, in the case of new editions in a product series, the determinants may include signals that originate from the reviews and the sales of editions that precede the focal product edition. Our analysis of 577 video games released in a series between 2000 and 2009 indicates that the reviews of earlier versions carry over to the reviews of the sequel by the same type of reviewer. We also find that expert reviews are influenced by the average review of previous editions by consumers and the average sales of previous editions of the product. This suggests that experts tend to adapt to the taste of consumers. Furthermore, it is found that a lack of consensus, between reviewers of a particular type, weakens the impact of average past reviews, whilst it magnifies the impact of the sales of earlier versions.     

Maternal Sensitivity and Child Responsiveness: Associations with Social Context,Maternal Characteristics,and Child Characteristics in a Multivariate Analysis

This study examined unique associations of multiple distal context variables (family socioeconomic status [SES], maternal employment, and paternal parenting) and proximal maternal (personality, intelligence, and knowledge; behavior, self‐perceptions, and attributions) and child (age, gender, representation, language, and sociability) characteristics with maternal sensitivity and child responsiveness in 254 European American mothers and their firstborn 20‐month‐olds. Specific unique relations emerged in hierarchical regression analyses. Mothers who worked fewer hours per week and reported less dissonance in their husbands' didactic parenting, whose children spoke using more vocabulary, and who reported less limit setting in their parenting and attributed their parenting failures to internal causes were observed to be more sensitive in their interactions with their children. Children in higher SES families, whose mothers worked fewer hours and attributed their parenting failures to internal causes, and who themselves used more vocabulary were observed to be more responsive in their interactions with their mothers. Although potential associations are many, when considered together, unique associations with maternal sensitivity and child responsiveness are few, and some are shared whereas others are unique.     

WELFARE LEAVERS AND RETURNERS

This study investigates a random sample of people who left welfare and a similar sample who returned to welfare in a mid-Atlantic state in 2002. Findings show that child-care difficulties are important barriers to employment and that they are bound together with other conditions of poverty such as adverse neighborhood conditions and other deprivations. Child care provision becomes difficult when neighborhoods are infested with drugs or guns or when caregivers must spend too much time finding the means to pay bills or rent and put food on the table. For the poorest groups, all these conditions negatively impact quality of life. The study's findings suggest social policy revisions that emphasize programs to improve the children's neighborhood environment and means of socialization, supplement caregivers’ income to levels sufficient to pay for child care, and remove inadequacies or inconsistencies in government child care provision.     

Overcoming Inertia: Do Automated Saving and Investing Strategies Work?

Many workers do not take advantage of savings opportunities provided to them at their workplace, nor do they always make wise investment decisions regarding employer plans. Various automated strategies have been implemented by employers with the objective of increasing retirement plan participation and, hence, the financial security of workers. Automatic strategies work by proactively arranging some type of action (e.g., plan enrollment) to occur unless people specifically opt out. This article examines and synthesizes previous empirical research about five automatic savings and investing strategies: (a) automatic retirement savings plan enrollment, (b) automatic contribution increases, (c) automatic portfolio rebalancing, (d) automatic rollovers, and (e) automatic investment plans. Advantages and disadvantages of each strategy are discussed, along with implications for financial educators.     

The Influence of Perceptions of Fairness on Performance Appraisal Reactions

The success of appraisal systems may well depend on ratees’ perceptions of fairness and reactions to important aspects of the appraisal process. My primary purpose is to integrate the literatures on fairness perceptions and appraisal reactions to test specific, heretofore untested, hypotheses. Consistent with predictions of Sweeney and McFarlin’s (Organizational Behavior and Human Decision Processes 55:23–40, 1993) two-factor model, results of structural equation modeling indicated that distributive justice influenced satisfaction with performance ratings and procedural justice influenced satisfaction with the appraisal system. Results indicated mixed support for Bies and Moag’s (Lewicki, Blair, Bazerman (eds) Research on Negotiation in Organization, JAI Press, Greenwich, CT, pp. 43–55, 1986) agent-system model as procedural justice (and distributive justice) had more influence on satisfaction with appraisal feedback than components of interactional justice perceptions. The implications of my results are discussed and suggestions for future research are offered.     

BAYESIAN BETA REGRESSION: APPLICATIONS TO HOUSEHOLD EXPENDITURE DATA AND GENETIC DISTANCE BETWEEN FOOT-AND-MOUTH DISEASE VIRUSES

There is considerable interest in understanding how factors such as time and geographic distance between isolates might influence the evolutionary direction of foot‐and‐mouth disease. Genetic differences between viruses can be measured as the proportion of nucleotides that differ for a given sequence or gene. We present a Bayesian hierarchical regression model for the statistical analysis of continuous data with sample space restricted to the interval (0, 1). The data are modelled using beta distributions with means that depend on covariates through a link function. We discuss methodology for: (i) the incorporation of informative prior information into an analysis; (ii) fitting the model using Markov chain Monte Carlo sampling; (iii) model selection using Bayes factors; and (iv) semiparametric beta regression using penalized splines. The model was applied to two different datasets.