Ranking opportunity sets: An approach based on the preference for flexibility

We describe a criterion to evaluate subsets of a finite set of alternatives which are considered as opportunity sets. The axioms for set comparison are motivated within the preference for flexibility framework. We assume the preference over the universal set of alternatives to be made of two disjoint binary relations. The result is the axiomatic characterization of a procedure which is formally similar to the leximax ordering, but in our case it incorporates the presence of some uncertainty about the decision-maker final tastes. Received: 20 January 1999/Accepted: 20 October 1999     

Properties of systems with two exchangeable Pareto components

The life lengths of the units in a system can be modelled by a bivariate distribution. In this paper, we suppose that the joint distribution of the units is a symmetric bivariate Pareto (Lomax) distribution. For this model, we obtain basic reliability properties for series and parallel systems. J. M. Ruiz Partially Supported by Ministerio de Ciencia y Tecnologia under grant BFM2003-02947 and Fundacion Seneca under grant 00698/PI/04.     

Life Satisfaction in Brazil: Testing the Psychometric Properties of the Satisfaction With Life Scale (SWLS) in Five Brazilian Samples

The aim of this paper was to validate the Brazilian-Portuguese version of the Satisfaction With Life Scale (SWLS), presenting evidence of its reliability and construct and criterion-related validity. A large Brazilian sample (2,180 participants), from five different populations (undergraduate and high school students, general population, elementary school teachers, and physicians), was considered. The results confirmed the single factorial structure and reliability (0.77 < Cronbach’s α < 0.88, mean α = 0.81) of the SWLS. Supporting its criterion-related validity, the SWLS correlated positively with positive affect and negatively with both negative affect and psychological distress across all five samples. The findings indicate that the Brazilian-Portuguese version of the SWLS is a valid instrument to use with diverse Brazilian samples.     

The Need to Establish the Organisation for the Prohibition of Biological Weapons: A Proposal for the Future

Biological weapons are considered, by the international community, as a weapon of mass destruction. When the Biological Weapons Convention (BWC) was negotiated during the 1960s and early 1970s, the negotiators considered unnecessary the establishment of an international organisation to supervise the implementation of the Convention’s provisions by the State parties. It is important to highlight that since the entry into force of the BWC, the international situation has significantly changed. For this reason perhaps the moment has arrived to consider again the proposal of settling down such an organisation in the framework of the strengthening the BWC.     

Estimating Engel curves: a new way to improve the SILC-HBS matching process using GLM methods

Microdata are required to evaluate the distributive impact of the taxation system as a whole (direct and indirect taxes) on individuals or households. However, in European Union countries this information is usually distributed into two separate surveys: the Household Budget Surveys (HBS), including total household expenditure and its composition, and EU Statistics on Income and Living Conditions (EU-SILC), including detailed information about households'' income and direct (but not indirect) taxes paid. We present a parametric statistical matching procedure to merge both surveys. For the first stage of matching, we propose estimating total household expenditure in HBS (Engel curves) using a GLM estimator, instead of the traditionally used OLS method. It is a better alternative, insofar as it can deal with the heteroskedasticity problem of the OLS estimates, while making it unnecessary to retransform the regressors estimated in logarithms. To evaluate these advantages of the GLM estimator, we conducted a computational Monte Carlo simulation. In addition, when an error term is added to the deterministic imputation of expenditure in the EU-SILC, we propose replacing the usual Normal distribution of the error with a Chi-square type, which allows a better approximation to the original expenditures variance in the HBS. An empirical analysis is provided using Spanish surveys for years 2012–2016. In addition, we extend the empirical analysis to the rest of the European Union countries, using the surveys provided by Eurostat (EU-SILC, 2011; HBS, 2010).     

Statistical considerations for assessing precision of heterogeneous duplicate measurements: An application to pharmaceutical bioanalysis

Duplicate analysis is a strategy commonly used to assess precision of bioanalytical methods. In some cases, duplicate analysis may rely on pooling data generated across organizations. Despite being generated under comparable conditions, organizations may produce duplicate measurements with different precision. Thus, these pooled data consist of a heterogeneous collection of duplicate measurements. Precision estimates are often expressed as relative difference indexes (RDI), such as relative percentage difference (RPD). Empirical evidence indicates that the frequency distribution of RDI values from heterogeneous data exhibits sharper peaks and heavier tails than normal distributions. Therefore, traditional normal-based models may yield faulty or unreliable estimates of precision from heterogeneous duplicate data. In this paper, we survey application of the mixture models that satisfactorily represent the distribution of RDI values from heterogeneous duplicate data. A simulation study was conducted to compare the performance of the different models in providing reliable estimates and inferences of percentile calculated from RDI values. These models are readily accessible to practitioners for study implementation through the use of modern statistical software. The utility of mixture models are explained in detail using a numerical example.     

EASING THE CONSTRAINTS OF MOTHERHOOD: THE EFFECTS OF ALL‐DAY SCHOOLS ON MOTHERS' LABOR SUPPLY

Low rates of female labor force participation (LFP) have been linked to the absence of childcare policies. This article examines the degree to which extending the school day by 3.5 hours in elementary schools, a large implicit childcare subsidy, affects LFP, the number of weekly hours worked, and the monthly earnings of females with elementary‐school‐age children. To do so, we exploit within‐individual variation in access to full‐time schools and a rotating panel of households that contains 12 years of individual‐level data on labor outcomes and sociodemographic characteristics. Results from long‐difference models show that extending the school day increases mothers' labor supply, increasing LFP by 5.5 percentage points and the number of weekly hours worked by 1.8. Moreover, these increases are accompanied by a raise in monthly earnings. (JEL I25, J13, J22)     

On the road toward the development of clothing size standards and safety devices for Chilean workers

The range of sizes used in Chile for clothing comes from criteria developed in continental Europe, mainly the EN 13402 standard. Any standard adopted by a country should consider the anthropometric dimensions of the user population, particularly to discern the ratio of garments for different size. Consequently, the purpose of this study was to propose standards for the size of clothing based on anthropometric characteristics of a sample of Chilean miners. The study was conducted in 447 male workers. The age and body weight were measured in each workers as well as their percentage of body fat. Anthropometric measurements for garments were made according to the criteria of the European Community (EN 13402-1) and ISO (8559- 1989). Body dimensions for the design of gloves, shoes, helmets and caps, clothes that cover the upper part of the body and clothes that cover the lower part were measured. The results obtained made it possible to establish the percentage of workers falling within the range of sizes that manufacturers consider as reference. One of the main conclusions of the study is the need to carefully consider a set of complementary anthropometric measures, which can help to improve the comfort of costumes, to the extent that the providers adapt their designs to the characteristics of Chilean workers.     

Conceptual design pattern for ergonomic workplaces

In this paper, we analyzed two laboratories of liquid chromatography (LC), separation technique of mixtures and identification of its components, in order to identify projectual gaps relating to the environment and the working station. The methodology used was the ergonomic analysis with interactional and participatory techniques applied during the activity performance. This work incorporated and adapted the concept developed by Alexander (1979)--pattern languages--passing from architectural projects to workstations project and physical arrangement of the work environment. The adaptation of the concept resulted in a list of recommendations, requirements and concepts that have brought design solutions for the problematic aspects observed in the ergonomic analysis. The employed methodology, strongly supported in ergonomics principles, and in interactional and participatory techniques, contributed to achieve our gold that is what we now call Conceptual Standards. The patterns go beyond of a usual model of book a of ergonomics specification, once incorporating the viewpoint of the end user, it is also a set of best project practices and of project management in conception ergonomics.