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."     

Thank God you're here: the coming generation and their role in future‐proofing Australia from the challenges of population ageing

Like much of the industrialised world, Australia's population is ageing, the implications of which are twofold: increasing demand for publicly funded services and a decline in the supply of prime working‐age people. In grappling with the challenges of a diminishing workforce, the Australian Government is currently relying on its migration programs to provide both the much‐needed labour and skills for the resource boom and also to stimulate the economy through population growth. However, there may be another, not yet fully considered solution to the upcoming demographic problem. This paper investigates how the grandchildren of the baby boomers, termed here the Thank God You're Here generation (Gen TGYH), might impact on Australia's predicted workforce shortage. This generation of workers will enter the labour force as the last of the baby boomers reach retirement age, and will not only be bigger in size than preceding generations (Y, X and Baby Boomers), but also potentially be better educated than the retiring generation. This paper will also canvas the opportunities for both Gen TGYH and employers as well as the challenges for policymakers and governments in maximising the opportunity provided by this generation in the Australian economy.     

Do cultural orientations moderate the relation between Chinese adolescents’ shyness and depressive symptoms? It depends on their academic achievement

We examined the moderating roles of individualistic and collectivistic cultural orientations and academic achievement on the relation between Chinese adolescents’ shyness and depressive symptoms. A sample of Chinese adolescents (N = 492) from an urban school participated in the study during seventh (T1) and eighth (T2) grades. Adolescents self‐reported their shyness, cultural orientations, and depressive symptoms. The school provided records of their academic achievement. Concurrently, shyness and individualism were positively whereas collectivism and academic achievement were negatively, associated with adolescents’ depressive symptoms. Longitudinally, T1 shyness (but not individualism, collectivism, or academic achievement) predicted T2 depressive symptoms after controlling for stability in depressive symptoms. Concurrent relations between shyness and depressive symptoms were moderated by adolescents’ cultural orientations. Specifically, collectivism was protective whereas individualism was harmful, for shy adolescents’ adjustment. Furthermore, collectivism and academic achievement jointly moderated the relations between shyness and depressive symptoms concurrently and longitudinally. The results suggest that cultural orientations may influence shy adolescents’ depression symptoms through individual‐level self‐evaluation, and indicate that cultural factors and academic achievement need to be considered comprehensively for understanding and improving shy Chinese adolescents’ psychological adjustment.     

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.