Multivariate distributions defined in terms of contours

The paper deals with the problem of using contours as the basis for defining probability distributions. First, the most general probability densities with given contours are obtained and the particular cases of circular and elliptical contours are dealt with. It is shown that the so-called elliptically contoured distributions do not include all possible cases. Next, the case of contours defined by polar coordinates is analyzed including its simulation and parameter estimation. Finally, the case of cumulative distribution functions with given contours is discussed. Several examples are used for illustrative purposes.     

Expected sample moments of concomitants of selected order statistics

In this paper, the task of determining expected values of sample moments, where the sample members have been selected based on noisy information, is considered. This task is a recurring problem in the theory of evolution strategies. Exact expressions for expected values of sums of products of concomitants of selected order statistics are derived. Then, using Edgeworth and Cornish-Fisher approximations, explicit results that depend on coefficients that can be determined numerically are obtained. While the results are exact only for normal populations, it is shown experimentally that including skewness and kurtosis in the calculations can yield greatly improved results for other distributions.     

International and internal migration decision making: a value-expectancy based analytical framework of intentions to move from a rural Philippine province

"The study compares determinants of internal and international migration intentions, drawing upon interview data from a sample of adults in Ilocos Norte, a largely rural province in the Philippines. A regression model is applied to test the relative determinants of intentions to migrate to Manila and to Hawaii. The study is based on a value-expectancy model of migration decision making. The results document the importance of subjective expectations related to the attainment of different values and goals in Manila and Hawaii."     

Bivariate,multivariate, and matrix variate normal characterizations: A brief survey II

The paper entitled “Bivariate and Multivariate Normal Characterizations: A Brief Survey,” by Hamedani, which was published in 1992, covered the published characterizations of bivariate and multivariate normal (MVN) distributions from 1941 to 1991. The present work is a follow-up to the 1991/1992 survey which includes not only characterizations of the bivariate and MVN distributions, but also characterizations of the matrix variate normal distribution, which have appeared from 1991/1992 to the present.     

A population sample registry for public health survey investigations: methods,lessons, and successes

Public health relies on sample surveys to monitor the health of populations and investigate factors that contribute to population health and illness. Such investigations require surveying individuals who are selected in ways that support statistical inference to the population. Faced with rising costs and declining participation, survey researchers are exploring economical ways to recruit samples that validly represent larger populations. The current report describes an innovative resource, the Colorado Adult Population Sample–Survey Research Registry, which maintains survey access to respondents from a probability-based state health survey. We describe recruitment and retention strategies, explore representativeness, report several studies that used the registry, and discuss future directions.     

The Good Grandparent: Perspectives of Young Adults

As life expectancy increases, the role of grandparent has increased in duration and is continually adapting as families change in structure, function and form. Across the past several decades, researchers have examined grandparenting styles, finding some consistency as well as the emergence of newer styles, and evidence that grandparenting styles are related to the age and gender of both the grandparents and the grandchildren. In this study, we investigated young adults’ perceptions of grandparenting quality. University Students (N?=?470) from a Midwestern university responded to an online survey that asked them to evaluate the quality of their grandparents grandparenting now and at two retrospective points in time, childhood and adolescence. We hypothesized that the grandparents' performance of multiple styles of their role would be related to grandparenting quality. In addition, we expected that preferred grandparental roles would vary in relation to grandchildren's gender. The results of regression analysis indicated that, although grandparenting quality tended to decline across the respondents' developmental stages, higher ratings at an earlier stage were related to higher ratings at the latter two stages. Further, grandsons preferred grandparents who performed as supporters and advisors, whereas granddaughters preferred grandparents who functioned as supporter and friend. Overall, grandmothers were likely to be the more significant grandparent. Continual research on both grandchildren and grandparents will be needed to chronicle the development of the grandparental role in changing times.