Estimation of dependence between paired correlated failure times in the presence of covariate measurement error

Summary. In many biomedical studies, covariates are subject to measurement error. Although it is well known that the regression coefficients estimators can be substantially biased if the measurement error is not accommodated, there has been little study of the effect of covariate measurement error on the estimation of the dependence between bivariate failure times. We show that the dependence parameter estimator in the Clayton–Oakes model can be considerably biased if the measurement error in the covariate is not accommodated. In contrast with the typical bias towards the null for marginal regression coefficients, the dependence parameter can be biased in either direction. We introduce a bias reduction technique for the bivariate survival function in copula models while assuming an additive measurement error model and replicated measurement for the covariates, and we study the large and small sample properties of the dependence parameter estimator proposed.     

Pseudo–Modelling of Outliers for Estimation of Regression And Time Series Models

This paper documents situations where the variance inflation model for outliers has undesirable properties. The model is commonly used to accommodate outliers in a Bayesian analysis of regression and time series models. The alternative approach provided here does not suffer from these undesirable properties but gives inferences similar to those of the variance inflation model when this is appropriate. It can be used with regression, time series, and regression with correlated errors in a unified way, and adheres to the scientific principle that inference should be based on the data after obvious outliers have been discarded. Only one parameter is required for outliers; it is interpretable as the a priori willingness to remove observations from the analysis.     

I'm Telling! The Content, Context, and Consequences of Children's Tattling on their Siblings

Tattling on siblings was observed in 40 families with 2- and 4-year-old children. All but 5 children reported sibling misbehaviour to parents with younger siblings tattling largely to recruit parental help in resolving conflict issues, and older siblings tattling both in the context of conflict and merely to inform parents of their siblings' misbehaviour. Parents rarely reprimanded children for tattling, but either ignored it, or responded to information in tattlers' reports regardless of context or whether older or younger children tattled. Children did not tattle equally on all sibling transgressions, but emphasized physical aggression and property damage, issues that also elicited parental discipline. Tattling is discussed in relation to children's understanding of the dynamics and moral standards of family life.     

A tool for selecting residential child care workers: an initial report

What strengths and talents make an outstanding child care worker? How can these qualities be measured? How can one predict whether an individual will succeed as a child care worker? The authors attempt to answer these questions by focusing on the "life themes" of highly rated child care workers and using a technique to measure these themes.     

Institutional Voids,Economic Adversity and Inter‐firm Cooperation in an Emerging Market: The Mediating Role of Government R&D Support

This paper examines the mediating mechanism of the relationship between institutional voids (IVs) and inter‐firm cooperation and the moderating role of economic adversity in the context of small and medium‐sized enterprises (SMEs) based in emerging markets. The hypotheses are tested using time‐lagged survey data from 214 SMEs in Ghana. The findings provide support for the hypotheses by showing that: (1) IVs positively influence the use of government research and development (R&D) support; (2) the use of government R&D support mediates the relationship between IVs and inter‐firm cooperation; and (3) economic adversity positively moderates the relationship between IVs and the use of government R&D support. The findings contribute to understanding the role of IVs in inter‐firm cooperation. The wider implications for theory and practice are examined.     

West and Central Africa

This article reviews scientific and other literature during the 1990s that links migration and mobility with the spread of sexually transmitted diseases (STDs), including HIV/AIDS. The focus is on key population groups linked to the spread of HIV and STDs in West and Central Africa: migrant laborers, truck drivers, itinerant traders, commercial sex workers (CSWs), and refugees. Countries with high emigration and immigration tend to have high levels of HIV infection, with the exception of Senegal. The main destination of immigrants are Senegal, Nigeria, and Cote d'Ivoire in West Africa and Cameroon, Congo, Gabon, and Congo in Central Africa. The risk of infection and the spread of HIV is variable among migrants. There is little in the literature that substantiates hypotheses about the strong association between migration and HIV-positive status. Information is needed on the duration, frequency of return visits, living conditions, sexual activities with multiple partners, and information before departure, along the routes, at final destination, and at the time of returns. Action-based research in five West African countries (Burkina Faso, Cote d'Ivoire, Mali, Niger, and Senegal) should produce results in late 1998. Comparable studies in Central Africa are unknown. Regional studies should be complemented by local studies. Prevention would benefit from studies on the relative size of these five population groups by geographic location.     

Illegal immigrants in Canada: recent developments

Immigration policies and their management in a country like Canada have long been an interesting and instructive study for other countries. 1) With borders naturally protected by great distance from almost all migrant routes; 2) with a long, undefended border with the US and a further 3000 kilometers to its border on the south; 3) with a parliamentary system capable of comparatively rapid legislative and administrative responses to problems; and 4) with a relatively small legal, and even smaller illegal, population Canada had historically "experimented" with novel, often quite creative, immigration policies and programs to both encourage and control the increases in its population. This paper summarizes what Canada did and is doing in response to am important item of public policy--the entry and presence of illegal migrants. Canada has experimented with 1) discretionary amnesty for long-term illegals with a capacity to be successfully integrated into Canadian life, 2) tighter border controls with the extended use of the visitor's visa, and 3) employer sanctions. To address the problem more substantively, however, requires detailed study and significant change, including legislative change.