Tests of symmetry based on transformed empirical processes

A probability distribution function F is said to be symmetric when 1 ‐ F(x) ‐ F(‐x) = 0 for all x∈ R. Given a sequence of alternatives contiguous to a certain symmetric F₀, the authors are concerned with testing for the null hypothesis of symmetry. The proposed tests are consistent against any nonsymmetric alternative, and their power with respect to the given sequence can easily be optimized. The tests are constructed by means of transformed empirical processes with an adequate selection of the underlying isometry, and the optimum power is obtained by suitably choosing the score functions. The test statistics are very easy to compute and their asymptotic distributions are simple.     

L’intergouvernementalité en reconstruction : le cas du Mexique

Since the 1930s, Mexico has had a dominant party, the Partido Revolucionario Institucional; and, despite the country’s federal constitution, decision-making has been so centralized that few powers have been left to the states. Recent attempts to break with this tradition and decentralize educational, health and welfare policy from the federal level to the states and big cities are examined. Three trends might unfold in the future: the establishment of an effective, multicentered decentralization; a surface decentralization without any real impact; or the fragmentation of policies and their impact. The foreseeable consequences of these three possibilities come under discussion. — Special issue: Latin America.     

Bivariate income distributions with lognormal conditionals

In this paper, the most general bivariate distribution with lognormal conditionals is fully characterized, using the methodology proposed by [3]. The properties of the new family are studied in detail, including marginal and conditional distributions, regression functions, dependence measures, moments and inequality measures. The new distribution is very broad, and contains as a particular case the classical bivariate lognormal distribution. Several subfamilies are studied and a generalization of the basic model is discussed. Finally, we present an empirical application. We estimate and compare the basic model proposed in the paper with a classical model, using data from the European Community Household Panel in different periods of time.     

The Effects of Perceived Barriers,Role Models,and Acculturation on the Career Self‐Efficacy and Career Consideration of Hispanic Women

This study used path analysis to examine the relationship between perceived barriers, acculturation, and role model influence on the career self‐efficacy and career considerations of a sample of Hispanic women. Two path models were examined. The male‐dominated model accounted for 15% of the variance, and the female‐dominated model accounted for 26% of the variance. No relationship was found between the variables of interest and male‐dominated career self‐efficacy and consideration. However, perceived barriers were related to female‐dominated career consideration and Anglo acculturation significantly contributed to female‐dominated career self‐efficacy. Results are discussed with regard to career practice and research with Hispanic women.     

Sample Size and Power Calculation in Comparing Diagnostic Accuracy of Biomarkers with Pooled Assessments

When testing of a biomarker is costly, pooling of samples becomes a useful and efficient alternative (Faraggi et al., 2003). In this paper, we develop procedures for sample size and power calculations for planning a study comparing the accuracy of biomarkers in diagnosis of diseases with pooled samples. Explicit formulas are derived for several important pooling strategies. The effects of pooling samples on sample size and power of the test are also discussed.     

Trouble en Route: Drug Trafficking and Clientelism in Rio de Janeiro Shantytowns

This article examines the ways that endemic drug trafficking has affected local level politics in Rio de Janeiro, Brazil. Drawing on ethnographic analysis of political exchanges in the 1998 national elections in three favelas (shantytowns), I argue that drug trafficking has changed the practice of clientelism. Evidence and analysis in this paper will show that the persistence of drug trafficking in the city has led to the emergence of a two-tiered clientelist system in which politicians make exchanges with traffickers who then, in turn, provide some benefits to favela residents in return for their votes. This results in an arrangement that provides votes to politicians and limited assistance to the poor but does little to build the legitimacy of the political system.

Confidence Intervals for the Youden Index and Corresponding Optimal Cut-Point

A global measure of biomarker effectiveness is the Youden index, the maximum difference between sensitivity, the probability of correctly classifying diseased individuals, and 1-specificity, the probability of incorrectly classifying healthy individuals. The cut-point leading to the index is the optimal cut-point when equal weight is given to sensitivity and specificity. Using the delta method, we present approaches for estimating confidence intervals for the Youden index and corresponding optimal cut-point for normally distributed biomarkers and also those following gamma distributions. We also provide confidence intervals using various bootstrapping methods. A comparison of interval width and coverage probability is conducted through simulation over a variety of parametric situations. Confidence intervals via delta method are shown to have both closer to nominal coverage and shorter interval widths than confidence intervals from the bootstrapping methods.     

An Exponential Model for Damage Accumulation

In this article, we present a general model for predicting the fatigue behavior for any stress level and amplitude using the exponential model. Based on the Wöhler field for fixed stress level, a compatibility functional equation enables us to derive the general model with eight parameters. The problem of parameter estimation is then discussed and some methods are described. Some examples are finally presented to illustrate the derived model and the proposed methods of estimation.     

SOCIAL HIERARCHIES: A LABORATORY STUDY ON PUNISHMENT PATTERNS ACROSS NETWORKS

We experimentally study punishment patterns across network structures, and their effect on cooperation. In a repeated public goods setting, subjects can only observe and punish their neighbors. Centralized structures (like the star network) outperform other incomplete networks and reach contribution levels like the ones observed in a complete network. Our results suggest that hierarchical network structures with a commonly observed player benefit more from sanctions not because central players punish more, but because they follow, and promote, different punishment patterns. While quasi-central players in other incomplete architectures (like the line network) retaliate, and get trapped in the vicious circle of antisocial punishment, central players in the star network do not punish back, increase their contributions when sanctioned by peripheral players, and sanction other participants in a prosocial manner. Our results illustrate recent field studies on the evolutionary prevalence of hierarchical networks. We document a network-based rationale for this positive effect in an identity-free, fully anonymous environment. (JEL C72, C91, C92, D90, H41)     

Ivies, extracurriculars, and exclusion: Elite employers’ use of educational credentials

Although a robust literature has demonstrated a positive relationship between education and socio-economic attainment, the processes through which formal schooling yields enhanced economic and social rewards remain less clear. Employers play a crucial role in explaining the returns to formal schooling yet little is known about how employers, particularly elite employers, use and interpret educational credentials. In this article, I analyze how elite professional service employers use and interpret educational credentials in real-life hiring decisions. I find that educational credentials were the most common criteria employers used to solicit and screen resumes. However, it was not the content of education that elite employers valued but rather its prestige. Contrary to common sociological measures of institutional prestige, employers privileged candidates who possessed a super-elite (e.g., top four) rather than selective university affiliation. They restricted competition to students with elite affiliations and attributed superior abilities to candidates who had been admitted to super-elite institutions, regardless of their actual performance once there. However, a super-elite university affiliation was insufficient on its own. Importing the logic of university admissions, firms performed a strong secondary screen on candidates’ extracurricular accomplishments, favoring high status, resource-intensive activities that resonated with white, upper-middle class culture. I discuss these findings in terms of the changing nature of educational credentialism to suggest that (a) extracurricular activities have become credentials of social and moral character that have monetary conversion value in labor markets and (b) the way employers use and interpret educational credentials contributes to a social closure of elite jobs based on socio-economic status.