Bayesian nonparametric estimation of a copula

A copula can fully characterize the dependence of multiple variables. The purpose of this paper is to provide a Bayesian nonparametric approach to the estimation of a copula, and we do this by mixing over a class of parametric copulas. In particular, we show that any bivariate copula density can be arbitrarily accurately approximated by an infinite mixture of Gaussian copula density functions. The model can be estimated by Markov Chain Monte Carlo methods and the model is demonstrated on both simulated and real data sets.     

The effects of Project SUCCESS on student academic performance: a quasi-experimental study

Project SUCCESS (PS) is a substance use prevention program that targets indicated high school students. We used archival data to explore the program's effects on students' academic achievement and disciplinary problems. It is essential to demonstrate such effects, if prevention curricula are to survive in schools that face multiple competing demands for class time. Using a quasi-experimental design that compared students exposed to the program to those not exposed in five schools, we examined the effects of PS on grades, absenteeism, and disciplinary problems. Using longitudinal analyses that linked individual students' program exposure data to their academic performance, we found that PS had a positive impact on both grades and absenteeism for two years following exposure. We note that these findings are particularly fortuitous, as PS was not designed to affect these outcomes. We recommend that future evaluations of school-based prevention curricula routinely include academic performance.     

Tracking residential outcomes of supported independent living programs for persons with serious mental illness

This study seeks to document patterns and reasons of leaving housing, and identify factors associated with different types of exits for a cohort of 452 residents with serious mental illness entering supported independent living (SIL) in Philadelphia, PA. The study cohort was tracked through an integrated administrative database comprised information on basic demographic and clinical characteristics, length of stay, homeless shelter use, and publicly funded behavioral health services use. A convenience sample of 46 SIL leavers and their support staff provided data on scenarios of leaving. The findings of this study suggest that departure from SIL is not a unitary phenomenon, but involving plausibly favorable as well as unfavorable circumstances. Multivariate analysis based on administrative tracking data suggests demographic and clinical factors, housing setting, and service use factors to have effects on leaving SIL and distinct types of exit examined in this study. Data procured from the convenience sample highlight the potential roles that program rules and resident–staff relationships play in affecting housing tenure. Implications of the findings for the development of permanent supportive housing for persons with serious mental illness are discussed.     

Workplace Change and Employee Mental Health: Results from a Longitudinal Study

This study is intended to improve understanding of the impact of workplace change on employee mental health and well‐being. We construct and test a comprehensive measure of organizational change, which is then applied in a prospective longitudinal study of nearly 5400 employees in six UK National Health Service Trusts. Self‐rated mental health was assessed using the 12‐item version of the General Health Questionnaire (GHQ). Just under a quarter of the sample were at increased risk of psychiatric morbidity (‘cases’). After controlling for a wide range of personal characteristics and work variables, it was found that respondents who reported an increase in the amount of work over the previous year were more likely to be classed as GHQ cases, whereas increased training and promotion and improved job security had a beneficial effect on employee mental health (less likelihood of being GHQ cases). Quantity or degree of change showed a somewhat ambiguous relationship with GHQ status. Our findings challenge the assumption that change will necessarily have an adverse effect on health, indicating areas, such as promotion and development, where a positive impact might be anticipated.     

Indigenous rights and internal wars: The Chiapas conflict at 15 years

This article examines the origins and outcomes of the indigenous-based Zapatista rebellion launched 15 years ago in Chiapas, Mexico. The precursors responsible for the resistance movement are assessed, as well as the proximate events which convinced the indigenous communities to embrace a militarized approach. International relations conflict theory is plumbed for explanations of the conflict and for conflict resolution strategies relevant to this particular event. This study finds that the conflict in Chiapas was the consequence of two antecedent conditions – systematic human rights abuses and extreme material deprivation; and two proximate factors – NAFTA ratification and pending revisions to communal land laws. The article also explains how violence mitigation was subsequently achieved as a result of the behavior of state and non-state actors.     

Exploring the Roles of Extracurricular Activity Quantity and Quality in the Educational Resilience of Vulnerable Adolescents: Variable- and Pattern-Centered Approaches

This longitudinal study examines how extracurricular activity involvement contributes to "educational resilience"—the unexpected educational attainments of adolescents who are otherwise vulnerable to curtailed school success due to personal- and social-level risks. Educationally vulnerable youth characterized by significant risks and an absence of assets were identified during early adolescence (approximately age 14) using measures of academic motivation, achievement, and mental health as well as family, school, and peer contexts. Using a mixture of variable- and pattern-centered analytic techniques, we investigate how both the total amount time that vulnerable youth spent in positive extracurricular activities and the specific pattern of their extracurricular activity involvement during late adolescence (approximately age 17) predict their subsequent enrollment in college during early adulthood (up through approximately age 21). Educational resilience was predicted uniquely by some, but not all, activity patterns. These results suggest that positive extracurricular activity settings afford vulnerable youth developmentally appropriate experiences that promote educational persistence and healthy development .     

Perfect and total altruism across the generations

The traditional formulation of the altruism model has altruistic terms that relate solely to other parties’ felicities from consumption. But if those others are altruistic as well, their altruism benefits are being neglected. Total altruism takes the total utilities of others, rather than their mere felicities, as the basis for altruistic valuations. We assess total altruism in an intergenerational world. Perfect altruism, a concept due to Ramsey (Econ. J. 38(152):543–559, 1928), requires that a generation value itself relative to its successor as it would any two consecutive generations. Total altruism and perfect altruism prove to be incompatible concepts. Total altruism is only meaningful when there is some generational selfishness. The analysis considers both forward-looking and forward and backward-looking altruism.     

A COMMENT ON THE COST OF NEW ISSUES OF COMMON STOCK

According to the constant growth model and perceived finance theory, the cost of new external equity exceeds the cost of retained earnings due to flotation costs and underpricing. Carlson and Dietz [1] have recently argued that the constant growth model is operationally inadequate whenever the net proceeds from the issuance of a new share differ from book value. Specifically, they contend that the cost of new external equity is less than the cost of retained earnings whenever the net proceeds from a new share exceed book value. We show that these conclusions stem from an error in interpretation and therefore that the constant growth model is valid regardless of the relationship between market prices and book value.     

ELECTED VERSUS APPOINTED REGULATORS: THEORY AND EVIDENCE

This paper contrasts direct election with political appointment of regulators. When regulators are appointed, regulatory policy becomes bundled with other policy issues the appointing politicians are responsible for. Because voters have only one vote to cast and regulatory issues are not salient for most voters, there are electoral incentives to respond to stakeholder interests. If regulators are elected, their stance on regulation is the only salient issue so that the electoral incentive is to run a pro‐consumer candidate. Using panel data on regulatory outcomes from U.S. states, we find new evidence in favor of the idea that elected states are more pro‐consumer in their regulatory policies. (JEL: H1, K2)