Estimating the stability of census-based racial/ethnic classifications: the case of Brazil

This study presents a method of estimating the degree to which people change their racial/ethnic identity from one census enumeration to another. The technique is applied to the classification of skin colour in Brazil (white, black, brown, yellow). For the period 1950-80, the findings show a deficit of 38 per cent in the black category and a gain of 34 per cent in the brown category, suggesting that a large proportion of individuals who declared themselves black in 1950 reclassified themselves as brown in 1980. Estimates for 1980-90, adjusted for the effects of international migration, reveal a similar pattern, although the magnitude of colour reclassification may have declined somewhat during the 1980s. Procedures to determine the stability of racial/ethnic identity produce data useful to recent policy initiatives that rely on demographic censuses to measure changes in the status of minority groups in less developed countries.     

Violence in the Brazilian favelas and the role of the police

Institutions should normally have an integrative influence. The family, for example, has the task of protecting and giving socio-emotional support to children, and schools should prepare young people for their future. Ideally the common goal of all of society's institutions is to secure the integration of youth and prevent or intervene against deviant behavior. But sometimes institutions provoke or even cause juvenile delinquency. The article discusses institutional influences and the role of the police in the criminal and violent situation in the favelas of Rio de Janeiro.Starting with an overview of the origins and the development of violence, crime, and drug trafficking in the favelas, the authors show how these slums arose. Their analysis examines the lack of a state presence with an integration policy to avoid social disintegration. Instead of social integration policy, there is a dual approach that both controls and produces violence. The article also presents the first results of a government attempt in 2000 to introduce a new police unit to stop the violence and improve the social opportunity structure of the residents of the favelas, especially young people.     

Work-to-Family Enrichment and Employees’ Well-Being: High Performance Work System and Job Characteristics

Research has demonstrated the importance of job characteristics to explain work-to-family enrichment (WFE) and the value of this enrichment to explain employees’ wellbeing. However, there is no comprehensive framework to explain the relationship between these variables. This study uses the Job Demands-Control-Support model as a guiding framework, and examines the relationship between these job characteristics and WFE and, more interestingly, the WFE as a mechanism for explaining the relationship between job characteristics and employees’ well-being. Furthermore, we analyzed the relationship of employees’ perceptions of High Performance Work System (HPWS) with job characteristics. With a sample of 1,390 employees from a Portuguese bank, job demands were found to be negatively related to WFE while autonomy and supervisor support displayed a positive relation. We also observed that WFE is an important mechanism to explain the relationship between these job characteristics and employees’ well being. As expected, HPWS was a relevant organizational characteristic to explain job characteristics, however, we observed that it was also directly related to WFE.     

Risk analysis in the brazilian stock market: copula-APARCH modeling for value-at-risk

Risk management of stock portfolios is a fundamental problem for the financial analysis since it indicates the potential losses of an investment at any given time. The objective of this study is to use bivariate static conditional copulas to quantify the dependence structure and to estimate the risk measure Value-at-Risk (VaR). There were selected stocks that have been performing outstandingly on the Brazilian Stock Exchange to compose pairs trading portfolios (B3, Gerdau, Magazine Luiza, and Petrobras). Due to the flexibility that this methodology offers in the construction of multivariate distributions and risk aggregation in finance, we used the copula-APARCH approach with the Normal, T-student, and Joe-Clayton copula functions. In most scenarios, the results showed a pattern of dependence at the extremes. Moreover, the copula form seems not to be relevant for VaR estimation, since in most portfolios the appropriate copulas lead to significant VaR estimates. It has found that the best models fitted provided conservative risk measures, estimates at 5% and 1%, in a scenario more aggressive.     

Metaheuristic algorithms for the bandwidth reduction of large-scale matrices

Journal of Combinatorial Optimization - This paper considers the bandwidth reduction problem for large-scale sparse matrices in serial computations. A heuristic for bandwidth reduction reorders the...