Multivariate log-Birnbaum–Saunders regression models

In this paper, we present a multivariate version of the skewed log-Birnbaum–Saunders regression model. This new family of distributions holds good properties such as marginal variables following univariate skewed log-Birnbaum–Saunders distributions, besides presenting the usual log-Birnbaum–Saunders distribution as a particular case. Furthermore, the model parameters are estimated through maximum-likelihood methods, a closed-form expression for the Fisher’s information matrix is presented, and testing hypothesis for model parameters is performed. Two real datasets are analyzed and results are discussed.     

Managers in the Global Economy: A Multilevel Analysis

We examine individual‐ and country‐level determinants of managerial employment, using data from the 1989 to 2009 waves of the World Values and European Values Surveys (n = 89,336 employed adults in 59 countries). Reflecting the rise of the transnational capitalist class, we find that factors related to globalization and international political institutions are most strongly associated with opportunities to join the managerial class relative to factors related to the business‐cycle or development. Additionally, in a subset of countries with detailed occupational information, we find that global trade has a particularly strong, positive association with the odds of being a corporate manager in a large firm.     

Interpreting demographic effects in duration analyses of first birth intervals

Estimated demographic effects in proportional hazard models of first birth intervals could reflect time-invariant differences in the risk of a birth, or differences in the timing of a shift in the risk, or both. This paper attempts to distinguish between these possibilities. The procedure is to estimate a more general model than the proportional hazard specification, in which the evolution of the risk of a birth can differ with demographic characteristics. The proportional hazard specification is nested within this more general model. Consequently, the consistency of the data with the risk or the timing interpretation of demographic effects can be tested. The data studied do not lead to a rejection of the proportional hazard specification.Department of Economics, University of Pennsylvania. The initial stage of this research was supported by a National Science Foundation Graduate Fellowship. I have benefited from insightful comments from David Bloom, Andrew Foster, Zvi Griliches, V. Joseph Hotz, Duncan Thomas, anonymous referees, and participants in seminars at Harvard University and the University of Pennsylvania, and in the Economic Demography sessions of the 1988 Population Association of America annual meetings. Any remaining errors are my own.     

Welfare State Development in Latin America and the Caribbean (1970s–2000s): Multidimensional Welfare Index,Its Methodology and Results

There is an ongoing debate between focalization and universalization on welfare policies as the best way to develop the welfare state in Latin America and the Caribbean. However, there is a need to develop a measure that exhibits the multidimensional nature of the welfare state, instead of focusing on the social spending dimension. Segura-Ubiergo (The political economy of the welfare state in Latin America: globalization, democracy and development. Cambridge University Press, New York, 2007) constructed a welfare effort index (WEI) to facilitate understand the relative degrees of welfare state development among Latin American countries. The WEI focuses mainly on social spending and ignores the other dimensions of welfare. Based on a comparative analysis of 17 Latin American countries and following the methodology of Segura-Ubiergo, a new index that aims at enriching the WEI was constructed. The new index is multidimensional in that it has eight indicators relating to three dimensions of welfare: social spending, coverage of welfare programs and outcome of welfare institutions. Principal component analysis was used for reducing the indicators into three indexes that represent three proposed dimensions of welfare. The combination of these three indexes gives the multidimensional welfare index. The results of the index account for more than 75 % of the data variance.     

Migration from Latin American countries to the United States: the economic,social and reproductive lives of Hispanic female immigrants, 1980

The authors describe the socioeconomic characteristics and fertility patterns of female immigrants from Latin America to the United States, with a focus on reasons for fertility differentials. "Using the one per cent public use sample from the 1970 and 1980 United States census, we first compare changes in socio economic characteristics from 1970 to 1980, and then examine the determinants of fertility of female immigrants to the United States, aged 16-49, from four Latin American areas or countries of birth.... The findings...suggest that there are direct effects of demographic, assimilation, and socioeconomic variables beyond those mediated by the variables in each of these sets. Further, regardless of the model, the effect of the clusters of demographic characteristics is most apparent. Age categories and marital status are the strongest indexed determinants of immigrant fertility.... The effect of education and employment is strong. Among assimilation variables, duration of residence and language ability are significant determinants of Hispanic immigrant fertility." (SUMMARY IN FRE AND SPA)     

Examining Familial-Based Academic Success Factors in Urban High School Students: The Case of Puerto Rican Female High Achievers

ABSTRACT

This article works to dispel the myth that Puerto Rican female urban high school students living in poverty are not capable of performing at high academic levels. This article attempts to counteract these beliefs by describing the four success factors that seven Puerto Rican female high school students attribute to their high academic achievement. These success factors are: (1) religiosity and extracurricular activities as sources of social capital, (2) affirming and maintaining a Puerto Rican identity, (3) maternal influences on students' academic achievement and, (4) the potential for caring teachers and other school staff to influence high academic achievement. Finally, our findings suggest that opportunities for Latinas and other youth of color are still inequitably structured in large, comprehensive high schools. Hence, we argue that schools must continue to bridge the large gap between themselves and the families/communities they serve and utilize the funds of knowledge and social capital that their students already bring to school.     

Leadership efficacy: Review and future directions

The concept of leader efficacy has received relatively little attention in the leadership literature. This is somewhat surprising given that effective leadership requires high levels of agency (i.e., deliberately or intentionally exerting positive influence) and confidence. This review uses existing theory and research on leader efficacy as a point of departure for proposing an expanded and multi-level framework for understanding the domain of leadership efficacy that includes leader, follower, and collective efficacies. The primary goals are to provide a conceptual framework to stimulate future theory and research on building efficacious leadership and to understand how such leadership develops and has implications for effective performance.     

Rivalry and strategic groups: what makes a company a rival?

Strategic group literature has generated a significant amount of research over recent decades. However, the rivalry implications of strategic group have remained unclear. This paper analyses rivalry and strategic groups in the house building industry in a small town from a cognitive approach. We consider rivalry as a subjective and directional phenomenon. Estimating rivalry as the direct identification of competitors we try to explain whether similarity affects rivalry and what factors make a company a “rival”. Results show that perceived rivalry is strongly related to size, past performance, subjective similarity and strategic group structure.

A reactive tabu search algorithm for the vehicle routing problem with simultaneous pickups and deliveries

The vehicle routing problem with pickups and deliveries (VRPPD) extends the vehicle routing problem (VRP) by allowing customers to both send and receive goods. The main difficulty of the problem is that the load of vehicles is fluctuating rather than decreasing as in the VRP. We design a reactive tabu search metaheuristic that can check feasibility of proposed moves quickly and reacts to repetitions to guide the search. Several new best solutions are found for benchmark problems.