Accuracy of approximate progressively censored reliability sampling plans for exponential models

Reliability sampling plans provide an efficient method to determine the acceptability of a product based upon the lifelengths of some test units. Usually, they depend on the producer and consumer’s quality requirements and do not admit closed form solutions. Acceptance sampling plans for one- and two-parameter exponential lifetime models, derived by approximating the operating characteristic curve, are presented in this paper. The accuracy of these approximate plans, which are explicitly expressible and valid for failure and progressive censoring, is assessed. The approximation proposed in the one-parameter case is found to be practically exact. Explicit lower and upper bounds on the smallest sample size are given in the two-parameter case. Some additional advantages are also pointed out.     

Homicide Rates in a Cross‐Section of Countries: Evidence and Interpretations

This study uses a regression analysis to explore the cross‐country variation in homicide rates for a large sample of countries. It starts by identifying seven significant regional variables, to which traditional socioeconomic, cultural, and institutional variables are added and tested. The importance of institutions, culture, and other factors affecting homicide rates is discussed. One unexpected finding is a curious relationship between the level of education and homicide rates: while an increase in male education tends to reduce homicide rates, an increase in female education tends to increase homicides. Several possible interpretations for this phenomenon are proposed. The study points to relatively unexplored areas of research in order to better understand homicide variation around the world.     

Working mothers’ decisions on childcare: the case of Spain

This paper aims to analyze household decisions regarding the childcare of young children. We present two specifications. The first one assumes a sequential decision process. Firstly, parents choose between paid or unpaid care and, secondly, those who opt for paid childcare must decide whether to take their children to a nursery or pre-school or employ somebody to care for them. The second specification is a multinomial Logit in which it is assumed that parents choose from three alternatives: unpaid care, paid care by a nanny, and center-based care. We apply our models to a sample of working mothers with children under three. The database used is the 2008–2010 Spanish Survey of Quality of Working Life (Encuesta de Calidad de Vida en el Trabajo). The results are in line with previous work: Parental education, family composition, income and the characteristics of the mother’s job are important factors in determining the type of childcare chosen for under-three-year-olds.     

Estimating utility functions using generalized maximum entropy

This paper estimates von Neumann and Morgenstern utility functions using the generalized maximum entropy (GME), applied to data obtained by utility elicitation methods. Given the statistical advantages of this approach, we provide a comparison of the performance of the GME estimator with ordinary least square (OLS) in a real data small sample setup. The results confirm the ones obtained for small samples through Monte Carlo simulations. The difference between the two estimators is small and it decreases as the width of the parameter support vector increases. Moreover, the GME estimator is more precise than the OLS one. Overall, the results suggest that GME is an interesting alternative to OLS in the estimation of utility functions when data are generated by utility elicitation methods.     

Rational-experiential thinking style and rational intergroup cooperation: the moderating role of intergroup conflict / Estilos de pensamiento racional-experiencial y la cooperación intergrupal racional: el rol modulador del conflicto intergrupal

Cooperative relationships between groups are difficult because of the high human capability to differentiate between in-group vs. out-group members. This obstacle exists even when the groups can obtain benefits for themselves from cooperation with other groups (rational cooperation). Based on an interactionist approach, the authors propose that personal (individual differences) and situational (conflicts) factors contribute to rational intergroup cooperation. The authors conducted a preliminary correlational study (Study 1) and an experimental investigation (Study 2). In Study 1, the authors examined, with 105 participants, the psychometric properties of the Spanish version of the Rational–Experiential Inventory (REI), measuring individual differences in information processing. In Study 2, the authors conducted an experimental investigation with 141 participants, testing the role of individual differences and conflict in intergroup rational cooperation. Findings of Study 1 showed that the scale has adequate psychometric properties. Results of Study 2 confirmed that the existence of both manipulated and perceived intergroup conflict reduces the magnitudes of the relationships between rational ability and rational cooperation. In addition, perceived intergroup conflict increased the magnitude of the links from experiential ability and experimental engagement to rational cooperation. Both individual differences and previous conflict have a role in predicting rational intergroup cooperation. According to the interactionist approach, personal and situational factors should be considered in the understanding of intergroup relationships.     

Social Accountability as an Innovative Frame in Civic Action: The Case of Rede Nossa São Paulo

In the past three decades, Brazil’s state and civil society have undergone a transformation. Non-profit organizations have proliferated, revealing new opportunities for participation, while sustainability and corporate social responsibility have produced new agendas for corporations. Against this background, accountability has emerged within the debate, particularly with regard to governmental transparency and efficiency. This paper examines the Rede Nossa São Paulo movement, which pledges social justice and sustainability and promotes social accountability as its main strategy to achieve its mission. Thus, the main objective of this study is to understand social accountability; more broadly, the goal is to examine governmental accountability in the mobilization process developed by Rede Nossa São Paulo by referring to the framing perspective as a core aspect in the understanding of social movements. Social accountability is presented as a frame that is composed of the union between movements that are historically bonded by the motto of social justice and other groups that are related to urban development and social and environmental responsibility.     

Who performs a stronger response to whom? Detecting individual competitive actions and reactions

This study analyzes the degree of competition through individual actions and reactions. Empirical support for this analysis has derived mainly from structural econometric models describing the nature of competition. This analysis extends the existing literature by empirically considering a direct measurement of competition through the analysis of the competitive actions and responses, and describing how firms compete within and between strategic groups. We estimate the firms’ conduct in the Spanish deposits market with 146 firms and 18,888 observations. This is a specially compelling context for the banking industry, in which a deregulation process gives rise to the adoption of aggressive strategies seeking to increase the market shares of deposit accounts; thus, producing a turbulent situation of increasing rivalry. Our results offer a deeper understanding of the firms’ competitive behavior, since we identify different patterns of actions and reactions depending upon the strategic group the firm belongs to.     

Asymmetries in Information Processing in a Decision Theory Framework

Research in psychology suggests that some individuals are more sensitive to positive than to negative information while others are more sensitive to negative rather than positive information. I take these cognitive positive–negative asymmetries in information processing to a Bayesian decision-theory model and explore its consequences in terms of decisions and payoffs. I show that in monotone decision problems economic agents with more positive-responsive information structures are always better off, ex ante, when they face problems where payoffs are relatively more sensitive to the action chosen when the state of nature is favorable.      

Modified minimax estimation of regression coefficients

Working with the linear regression model (1.1) and having the extraneous information (1.2) about regression coefficients the problem exists how to build estimators (1.3) with the risk (1.4) which enable to utilize the known information in order to reduce their risk as compared with the risk (1.6) of the LSE (1.5). Solution of this problem is known for the positive definite matrix T, namely in form for estimators (1.8) and (1.10).First, it is shown that the proposed estimators (2.6),(2.9) and (2.16) based on psedoinversions of the matrix L represent the solution of the problem of the positive semidefinite matrix T=L'L.Further, the problem of interpretability of estimators in the sense of the inequality (3.1) exists; it is shown that all mentioned estimators are at least partially interpretable in the sense of requirements (3.2) or (3.10).