An immune algorithm with stochastic aging and kullback entropy for the chromatic number problem

We present a new Immune Algorithm, IMMALG, that incorporates a Stochastic Aging operator and a simple local search procedure to improve the overall performances in tackling the chromatic number problem (CNP) instances. We characterize the algorithm and set its parameters in terms of Kullback Entropy. Experiments will show that the IA we propose is very competitive with the state-of-art evolutionary algorithms.     

A Generalized Estimating Equation in Longitudinal Data to Determine an Efficiency Indicator for Football Teams

Over the years football has attracted enormous interest from various fields of study, attracting attention both for its sporting and social aspects. Professional business operators consider football an important industry with enormous potential both in terms of its size and growth, and also because of indirect benefits due to the popularity gained by investors and management of football teams. The focus of the analysis has been on what characterizes most football clubs, and determines their particular economic and financial needs. The aim of this paper is to establish an efficiency measurement for football team financial resource allocation. In particular, we analysed the impact that the income statement, Net equity and Team value variables have on the points achieved by football teams playing in “Serie A” championship (Italian league). The method used in our study is a generalized estimating equation (GEE) for longitudinal count data. In addition we consider a coefficient of determination in the GEE approach based on Wald Statistics, and we propose a modified Mallow’s Cp for choosing the best model. Finally we propose an AFRSport index based on the differences between observed and theoretical points, in order to identify those teams that efficiently employ their financial resources.

     

Effort Observability,Incentive Systems,and Organizational Forms

This paper analyses the choice between a centralized and a decentralized organizational structure focusing on the relationship existing between the allocation of decision rights, the degree of observability of effort and the use of different compensation systems. Profitable production is realized thanks to good information being available during the project selection stage and hard work being performed in the implementation stage. Selection of projects may be made by the principal (hierarchy) or by the agent (delegation). Under the hierarchical system, the principal's participation in the design of projects allows her to gather useful information for the design of a more accurate compensation system. Therefore, we analyse the trade‐off between optimal use of available information and accuracy of incentive systems, which emerges in the choice of organizational form.     

Portability of Supplementary Pension Rights in the European Union

European Union (EU) legislation on portability of supplementary pension rights accrued by private-sector migrant workers is at an early stage. The recent directive on this topic, aiming to preserve accrued pension rights at least at the level guaranteed in the case of within-borders mobility, emphasizes the role of country-specific legislation on pension portability issues. This paper analyses EU as well as national pension portability regulation for a representative sample of EU countries, in the light of recent empirical evidence outlining the role of occupational pensions in individual job mobility choices in these countries.     

No-envy and Arrow's conditions

This paper analyzes the concept of envy-freeness in the framework of Arrovian social choice theory. We define various no-envy conditions and study their relationships with Arrow's condition of independence of irrelevant alternatives. We also propose a new condition, called Minimal Equity, that says that each individual must have the conditional power to veto at least one social state (for instance, a social state which is particularly unfair to him). We show that, under unrestricted domain, Pareto Optimality and a weak independence condition, Minimal Equity leads to an impossibility result. Received: 9 October 1997/Accepted: 27 May 1998     

Body Weight,Eating Patterns,and Physical Activity: The Role of Education

In this article, we empirically study the role of education attainment on individual body mass index (BMI), eating patterns, and physical activity. We allow for endogeneity of schooling choices for females and males in a mean and quantile instrumental variables framework. We find that completion of lower secondary education has a significant positive impact on reduction of individual BMI, containment of calorie consumption, and promotion of physical activity. Interestingly, these effects are heterogeneous across genders and distributions. In particular, for BMI and calorie expenditure, the effect of education is significant for females and is more pronounced for women with high body mass and low physical activity. On the other hand, the effect of education on eating patterns is significant mainly for males, being more beneficial for men with elevated calorie consumption. We also show that education attainment is likely to foster productive and allocative efficiency of individuals in the context of BMI formation. Given that the literature suggests that education fosters development of cognition, self-control, and a variety of skills and abilities, in our context it is thus likely to promote lifetime preferences and means of individuals, which in turn enable them to achieve better health outcomes. Education also provides exposure to physical education and to school subjects enhancing individual deliberative skills, which are important factors shaping calorie expenditure and intake. Finally, we show that in the presence of strong socioeconomic inequalities in BMI, education is likely to have a pronounced impact on healthy BMI for the disadvantaged groups, represented in our framework by females.     

Statistics and the Single Market

Abstract. At the end of 1992customs barriers will fall and the European Internal Market will be realized, as envisaged by the Single European Act signed in 1986 by the EEC's member countries. Statistical Offices are preparing to meet the new information requirements from all the economic and social forces of the new Europe. EUROSTAT planned a politically endorsed statistical programme and established the European Statistical Planning Committee, enlarging the tasks of the Conference of the Heads of National Statistical Institutes. Each National Statistical Institute is urgently required to improve the comparability of statistics and implement the harmonised projects of the European Statistical Programme. Official statistics will conform to the new requirements in order to supply the business world, national governments, the EEC authorities and public opinion with up-to-date information to face a wider, more open and competitive market. The business world will focus its attention on information on the flows by sectors and very small areas. Statistics on intra-community foreign trades will shift from customs bills to new tools more directly assigned to national statistical bodies. National governments and EEC countries will need more information on population behaviour as to employment, consumptions, use of leisure time, fruition of public facilities, and social security, as well as more precise estimates of GDP, now the basic contribution to EEC budget. Citizens and public opinion will ask for timely information on migrations, social mobility, income distribution. Demographic projections show the European population is progressively ageing, unemployment is bound to decrease and women are going to be more present within society and the labour market. Information on the home care of elderly people. health, environment, crime prevention and the status of women in general will have to be supplied. Presently Statistics Offices have greater experience in two essential domains: conceptual frameworks and the techniques for conceptual statistical representation of the investigated events. Moreover, the improving of computer technology will provide substantial help to survey methodologies and data processing.     

Social Confidence in Unions: A U.S.‐Canada Comparison

Cet article examine l’évolution des niveaux de confiance sociale envers les organisations syndicales au Canada et aux États‐Unis entre 1982 et 2006 en s'appuyant sur les données de la World Value Survey (WVS). Partant du constat que ces taux de confiance sont relativement similaires au sein de ces deux pays, nous appliquons un modèle de régression logistique sur les deux vagues de données les plus récentes du WVS (soit celle de 2000 et 2006) afin de mieux comprendre la propension des individus à faire confiance aux syndicats dans chaque contexte national en fonction de certaines de leurs caractéristiques sociales et politiques. Les résultats montrent des similitudes entre les deux pays (par exemple, les citoyens les plus progressistes et les plus jeunes ont généralement une plus grande confiance envers les syndicats), mais également des distinctions importantes (à titre d'exemple, seul au Canada les individus répondant à un profil de “classe ouvrière” manifestent une plus grande confiance envers les syndicats). This article examines changes in levels of social confidence in unions in Canada and the United States between 1982 and 2006 based on an analysis of the World Value Survey (WVS) data set. It considers why confidence rates are similar in the two countries, applying a logistic regression model to the two most recent WVS waves (i.e., 2000 and 2006) so as to bring out the effects of political and social differences on the propensity of individuals to trust unions in each national context. The results show similarities between the two countries (e.g., more progressive and younger citizens generally have greater confidence in unions), but also important distinctions (e.g., only in Canada do individuals with a working class profile appear to have greater confidence in unions).     

EVALUATING PENSION PORTABILITY REFORMS: THE TAX REFORM ACT OF 1986 AS A NATURAL EXPERIMENT ABSTRACT

This article exploits a change in the vesting rules for employer‐sponsored pension plans introduced by the Tax Reform Act of 1986 to identify the causal effect of pension portability legislation on workers' voluntary mobility decisions. We pool data from different years of the Survey of Income and Program Participation to estimate the impact of this reform using difference‐in‐differences methods. Our results suggest that the reform had a positive and significant impact on voluntary job mobility of the treatment group. (JEL J24, J44, J62, J63, J68)     

Nash Bargaining Theory,Nonconvex Problems and Social Welfare Orderings

In this paper we deal with the extension of Nash bargaining theory to nonconvex problems. By focussing on the Social Welfare Ordering associated with a bargaining solution, we characterize the symmetric Nash Bargaining Solution (NBS). Moreover, we obtain a unified method of proof of recent characterization results for the asymmetric single-valued NBS and the symmetric multivalued NBS, as well as their extensions to different domains.