Inference for step-stress accelerated life tests

In this paper we consider the more realistic aspect of accelerated life testing wherein the stress on an unfailed item is allowed to increase at a preassigned test time. Such tests are known as step-stress tests. Our approach is nonparametric in that we do not make any assumptions about the underlying distribution of life lengths. We introduce a model for step-stress testing which is based on the ideas of shock models and of wear processes. This model unifies and generalizes two previously proposed models for step-stress testing. We propose an estimator for the life distribution under use conditions stress and show that this estimator is strongly consistent.     

Mentoring Improves Acceptance of a Community Intervention For Court-Referred Male Persons in Need of Supervision (PINS)

Despite excellent community-based interventions for court-referred adolescent boys, low rates of retention in the initial phase of treatment often lower overall effectiveness. This study assessed the contribution of mentoring towards improving compliance with a community-based intervention for court-referred adolescent male Persons in Need of Supervision (PINS). Charts on 79 court-referred adolescent boys (mean age=14.28; SD=1.37) admitted to a community based intervention in a large metropolitan area were systematically reviewed for patterns of service utilization (mentoring and group treatment), familial history, and substance use and psychopathology. Male adolescent PINS who utilized mentoring were ten times more likely to remain in the community-based intervention during the initial 6 months. Following the initial 6 months period, utilization of group treatment, but not mentoring, was associated with retention in the community-based intervention and positive outcome. Community-based intervention for court-referred adolescents might include mentoring during the initial 6 months of treatment to improve compliance.     

Ordering conditional lifetimes of coherent systems

Consider a system of n components that has the property that there exists a number r  (r<n)$(r<n)$, such that if it is known that at most r components have failed, the system is still functioning with probability 1. Suppose that such a system is equipped with a warning light that comes up at the time of the failure of the rth component. The system is still working then, and we are interested in its residual life. In this paper we obtain some results which stochastically compare the residual lives of such systems with the same type, or with different types, of components. Some applications are given. In particular, we derive upper and lower bounds on the expected residual lives of such systems given that the warning light has not come up yet, and given that the component hazard rate functions are bounded from below or from above by a known constant.     

A general family of univariate stochastic orders

In this paper we introduce and study a family of univariate stochastic orders parameterized by a function h  . The usual stochastic order _?st${?}_{\mathrm{st}}$, and the total time on test transform order _?ttt${?}_{\mathrm{ttt}}$, are special cases of this new family. We study some properties of the new family, and we give some applications of it in actuarial science, reliability theory, and statistics.     

Worth a Third Read: Six Readers Recall Articles from the AJFT and ANZJFT

Six readers were asked to recall papers from earlier issues of this journal and to write briefly about what made these papers stand out in their minds. These readers have also been unable to resist the temptation to mention other papers which they would like to have had the time to discuss as well!     

Labor Migration,Remittances and Economic Well-being of Households in the Philippines

Labor Migration has long been viewed as a strategy adopted by the household unit to allocate family resources rationally to increase the flows of income and to raise family standard of living. The research reported here examines the extent to which remittances sent by Filipino overseas workers increase the income and standard of living of households in the Philippines. Data for the analysis were obtained from a representative sample of 2,388 households drawn in 1999–2000 from four major “labor sending” areas in the Philippines. The analysis compares households with and without overseas workers to estimate the contribution of remittances to household income and to household standard of living (measured once by an ‘objective’ indicator and once by a ‘subjective’ assessment). The data reveal that due to remittances the income of households with overseas labor migrants is considerably higher than the income of households without overseas workers. The data also reveal that remittances are used mostly for consumption purposes (e.g. purchase of food, clothing, education, and goods) and that most of the difference in standard of living (whether measured on the ‘objective’ or the ‘subjective’ scale) between households with and without overseas workers are attributed to remittances. The implications of labor migration and the policy that encourages and supports labor migration for the Filipino society are evaluated and discussed.

Effectiveness of a psychosocial intervention model for persons with chronic psychiatric disorders in long-term hospitalization

The article describes a psychosocial model of intervention with psychiatric patients in long-term hospitalization in a psychiatric ward in Israel and reports the findings of the evaluation conducted of its effectiveness. The model was aimed at maintaining or improving the patients' functioning in four main areas: personal hygiene, environmental maintenance, occupational competency, and social and recreational activities. For each patient, an individualized intervention program was designed and implemented by a personal case manager appointed from the ward's clinical staff. The programs involved family and ward staff as well as the patients themselves. The evaluation, based on comparison of monthly data for 4 months before and 12 months during the intervention, showed significant improvement in all but two areas of functioning: social functioning and psychiatric status. The findings, although in need of confirmation in larger, representative samples of patients in Israel and elsewhere, hold promise for effective intervention with patients whose treatment today consists largely of medication.     

Occupational Destinations and Economic Mobility of Filipino Overseas Workers1

This study examines employment and occupational shifts experienced by Filipino overseas contract workers in the transition from country of origin to country of destination and examines the impact of labor migration on economic conditions and standard of living of the families left behind. Data for the analyses were obtained from a representative sample of 2,346 households drawn from four primary sending areas in the Philippines. The analyses focus on characteristics of the households and of the household members employed overseas. The findings reveal that a considerable number of overseas workers (both men and women) were unemployed prior to migration and that the overwhelming majority of these workers were recruited to fill low‐status (manual and service) occupations in the host country. The analysis demonstrates that the odds for Filipino overseas workers to be employed in low‐status occupations were extremely high, net of human capital characteristics, net of the occupations they held in the Philippines, and net of country of destination. Further analysis reveals that overseas employment is associated with a substantial increase in earnings (five‐fold for men and four‐fold for women). Comparison between households with and without overseas workers reveals that, net of household characteristics, the flows of income earned abroad are used to purchase household goods to improve standard of living. These findings provide firm support to expectations derived from the household theory of migration according to which labor migration is a strategy adopted by the household unit to allocate family resources rationally to increase the flows of income in order to raise the family standard of living.     

Institutional Structure and Immigrant Integration: A Comparative Study of Immigrants' Labor Market Attainment in Canada and Israel1

The present study focuses on the incorporation of immigrants from the former Soviet Union in two receiving societies, Israel and Canada, during the first half of the 1990s. Both countries conducted national censuses in 1995 (Israel) and 1996 (Canada), making it possible to identify a large enough sample of immigrants and provide information on their demographic characteristics and their labor market activity. While both Canada and Israel are immigrant societies, their institutional contexts of immigrant reception differ considerably. Israel maintains no economic selection of the Jewish immigrants and provides substantial support for newcomers, who are viewed as a returning Diaspora. Canada employs multiple criteria for selecting immigrants, and the immigrants' social and economic incorporation is patterned primarily by market forces. The analysis first examines the characteristics of immigrants who arrived in the two countries and evaluates the extent of selectivity. Consistent with our hypotheses, Russian immigrants to Canada were more immediately suitable for the labor market, but experienced greater difficulty finding and maintaining employment. Nevertheless, immigrants to Canada attained higher‐status occupations and higher earnings than their compatriots in Israel did, although the Israeli labor market was more likely to reward their investments in education.     

The Structure of Technology in a Multioutput Branch Banking Firm

We formulate and estimate a multioutput bank's cost function amenable for distinguishing between economies of scale and economies of network density. We find significant returns to network density, especially for smaller banks. Diseconomies of scale are found for the larger banks, whereas the hypothesis of constant returns to scale could not be rejected for the smaller banks.