The Generalized Pascal Triangle and the Matrix Variate Jensen-Logistic Distribution

This article defines the so called Generalized Matrix Variate Jensen-Logistic distribution. The relevant applications of this class of distributions in Configuration Shape Theory consist of a more efficient computation, supported by the corresponding inference. This demands the solution of two important problems: (1) the development of analytical and efficient formulae for their k-th derivatives and (2) the use of the derivatives to transform the configuration density into a polynomial density under some special matrix Kummer relation, indexed in this case by the Jensen-Logistic kernel. In this article, we solve these problems by deriving a simple formula for the k-th derivative of the density function, avoiding the usual partition theory framework and using a generalization of Pascal triangles. Then we apply the results by obtaining the associated Jensen-Logistic Kummer relations and the configuration polynomial density in the setting of Statistical Shape Theory.     

Aggregating Political Dimensions: Of the Feasibility of Political Indicators

Political indicators are widely used in academic writing and decision making, but remain controversial. This paper discusses the problems related to the aggregation functions they use. Almost always, political indicators are aggregated by weighted averages or summations. The use of such functions is based on untenable assumptions (existence of homogeneous substitution rates, total compensation, and strict monotonicity). We show through concrete examples how these hidden assumptions are likely to produce results that are basically an artifact of ad hoc decisions, which additionally contradict very fundamental notions common to all credible political theories. We suggest, also through example, that some—necessarily partial—solutions are possible.     

Internet use among community college students: implications in designing healthcare interventions

The Internet has become a commonly used venue for seeking healthcare information. Young adults search the Internet for health information more than any other group, yet little is known about use patterns among community college students. The authors surveyed a diverse community college to assess students' use of the Internet for health-related information. More than 80% had home Internet access, regardless of race or gender. Men and women searched for health information in almost equal numbers. Most students were interested in searching for diet/nutrition topics, and least interested in smoking information. Although the digital divide appears to be closing, varying levels of interest in a variety of important health topics remain. Understanding these differences could guide the design of more effective Web-based health interventions.     

The price of risk with incomplete knowledge on the utility function*

When a risk is exchanged, the exact value for the minimum price (positive or negative) that the purchaser (investor, or insurer) is willing to pay is given by the certainty equivalent wealth level, which in turn depends on his specific utility function. When this utility function is unknown, then only a sufficient condition on the price can ever be found. This paper provides methods for calculating such a sufficient condition, when only limited information on the utility function is known.     

Puerto rican drug users’ experiences of physical and sexual abuse: Comparisons based on sexual identities

This study integrates the results of quantitative and qualitative methods to elucidate the association between sexual identity and physical and sexual abuse among Puerto Rican drug users. A structured questionnaire was administered to 800 subjects in New York and 399 in Puerto Rico. A total of 93 subjects (7.9%) self‐identified as homosexual or bisexual. Gay males were significantly more likely than heterosexual males to report first occurrence of physical abuse by a family member in childhood. Both gay and bisexual males were more likely than their heterosexual counterparts to report first experiencing unwanted sex in childhood and intimate partner physical abuse later in life. Lesbians were more likely than female heterosexuals to report unwanted sex in childhood. Qualitative data were collected through in‐depth life histories with 21 subjects and suggest that gay and lesbian subjects perceive antihomosexual prejudice on the part of family members as one cause of childhood physical and sexual abuse.     

Political election on legal retirement age

In the context of the current debate surrounding the reform of pension systems, this paper analyzes the political economy of the legal retirement age. Using a life-cycle model in which individuals differ by age and by wage, we analyze the outcome of a majority voting process on the legal retirement age in a Pay-As-You-Go pension system. The results show that the older an individual is, the closer her optimal retirement age is to the status quo age. That is, the status quo retirement age acts as a magnet. Additionally, we find that the preferred legal retirement age of most of the working population increases when the pension system is more redistributive. We also observe a positive relationship between the preferred legal retirement age and the status quo age.     

To participate or not to participate: that is the question

Do I wish to participate or not to participate in this program? That is the question that young people ask themselves when considering a new opportunity. What can be done to increase the likelihood that they will choose to participate in out-of-school-time (OST) programs? This chapter describes a qualitative study that examined reasons for participating or not participating in OST programs. Some common reasons emerged, but the study also revealed differences among youth from different ethnic groups. It is clear that those who design and conduct programs must understand the processes through which diverse adolescents initiate their participation in programs and either persist or drop out. Given the apparent benefits of active participation in youth programs, it is important to remove barriers and increase access and, equally important, design programs that are of interest to youth in the contexts in which they live.     

A generalization of Jeffreys' rule for non regular models

ABSTRACT

We propose a generalization of the one-dimensional Jeffreys' rule in order to obtain non informative prior distributions for non regular models, taking into account the comments made by Jeffreys in his article of 1946. These non informatives are parameterization invariant and the Bayesian intervals have good behavior in frequentist inference. In some important cases, we can generate non informative distributions for multi-parameter models with non regular parameters. In non regular models, the Bayesian method offers a satisfactory solution to the inference problem and also avoids the problem that the maximum likelihood estimator has with these models. Finally, we obtain non informative distributions in job-search and deterministic frontier production homogenous models.     

The exponential Poisson logarithmic distribution

Abstract

In this article, we proposed a new three parameter lifetime distribution motivated mainly by lifetime issues, which generalizes the Exponential Poisson distribution proposed by Cancho et al. (2011) Cancho, V.G., Louzada-Neto, F., Barriga, G.D. (2011). The poisson-exponential lifetime distribution. Computat. Statist. Data Anal. 55:677–686.[Crossref], [Web of Science ®] , [Google Scholar]. We derive various standard mathematical properties of the proposed model including a formal proof of its probability density function and hazard rate function. The inference via the maximum likelihood approach is discussed. The performance of the maximum likelihood estimators, the likelihood ratio test and its power are studied by simulation. Finally, the proposed model is fitted to two real data sets and it is compared with several models.