Confidence Intervals for Reliability of Stress-Strength Models in the Normal Case

In this article, we propose some procedures to get confidence intervals for the reliability in stress-strength models. The confidence intervals are obtained either through a parametric bootstrap procedure or using asymptotic results, and are applied to the particular context of two independent normal random variables. The performance of these estimators and other known approximate estimators are empirically checked through a simulation study which considers several scenarios.     

Why are some more peer than others? Evidence from a longitudinal study of social networks and individual academic performance

Studies of peer effects in educational settings confront two main problems. The first is the presence of endogenous sorting which confounds the effects of social influence and social selection on individual attainment. The second is how to account for the local network dependencies through which peer effects influence individual behavior. We empirically address these problems using longitudinal data on academic performance, friendship, and advice seeking relations among students in a full-time graduate academic program. We specify stochastic agent-based models that permit estimation of the interdependent contribution of social selection and social influence to individual performance. We report evidence of peer effects. Students tend to assimilate the average performance of their friends and of their advisors. At the same time, students attaining similar levels of academic performance are more likely to develop friendship and advice ties. Together, these results imply that processes of social influence and social selection are sub-components of a more general a co-evolutionary process linking network structure and individual behavior. We discuss possible points of contact between our findings and current research in the economics and sociology of education.     

From an Agrarian to an Environmental,Food, and Natural Resource Base for Agricultural Policy: Some Reflections on the Case of the EC

Abstract The agriculture of the European Community (EC) has experienced significant changes in the last decade. From a situation of deficiency in agricultural and food production, the twelve-nation community has shifted to a situation of food overproduction. This change has also been characterized by a rapid decrease in the agricultural labor force and a decrease of its importance in the employment structure which has manifested itself in fewer, more efficient farms. This alteration of structural conditions has led to the emergence of a new set of agricultural issues. This article discusses these changes by underscoring the decline of agrarian-based issues and the emergence of environmental, food, and natural resource-based issues. It is maintained that EC agricultural policies have been instrumental in both the resolution of agrarian-based issues and in the creation of new problems embodied in the environmental, food, and natural resource-based policies. The combination of the demise of agrarian-based policies and the emergence of environmental, food, and natural resource-based policies is also employed as a theoretical perspective from which the evolution of the agricultural sector in the EC can be interpreted.     

Hidden information problems in the design of family allowances

We consider the optimal determination of family allowances in a model where some of the parents have higher ability to raise children than others. First-best policy gives both types of parents the same level of utility. If neither parental ability nor parental actions are fully observable, however, the policy maker has to take into account the incentive-compatibility constraint that more able parents should not find it profitable to mis-represent their true ability by investing less in their children, and having a lower number of children. The second-best policy induces more able parents to have the first-best number of children, and to invest in each child at the first-best level. Less able parents are induced to have fewer children than in first best, and will underinvest in each child. Whether the government should subsidize more the more able parents, or the less able ones, depends on the properties of the cost function. In second best, however, less able parents will end up with lower utility than more able parents whatever the cost function.All correspondence to Annalisa Luporini. The paper has benefitted from comments by three anonymous referees. Responsible editor: Junsen Zhang.     

Structural learning and estimation of joint causal effects among network-dependent variables

Statistical Methods & Applications - Bayesian networks in the form of Directed Acyclic Graphs (DAGs) represent an effective tool for modeling and inferring dependence relations among variables,...     

Public Sector Strategies in Curbing Corruption: A Review of the Literature

Public Organization Review - Corruption is widespread and preventive strategies to reduce corruption need to be adapted within the local context. Considering the United Nations (UN) Convention...     

Assessment of agricultural sustainability in European Union countries: a group-based multivariate trajectory approach

AStA Advances in Statistical Analysis - Sustainability of agriculture is difficult to measure and assess because it is a multidimensional concept that involves economic, social and environmental...     

Structural Reforms and Fiscal Discipline in Europe

In this paper we provide an overview on recent contributions on the effectiveness of the institutional framework operating in Europe to fulfil the objectives declared in the Lisbon Agenda under the fiscal constraints established in the Stability and Growth Pact. After a review of the Stability and Growth Pact as well as the Lisbon Strategy and the Sapir Report, we discuss the relations between fiscal policy and structural reform. Finally, we focus on 2D points in the EU debate on institutional reforms: government short-sightedness and the coordination of national fiscal policies at the European level.