Mixtures of increasing failure rate distributions (IFR) can decrease at least in some intervals of time. Usually this property is observed asymptotically as time tends to infinity , which is due to the fact that a mixture failure rate is ‘bent down’, as the weakest populations are dying out...

It has been argued recently that a society’s ‘gender system’ influences parents’ sex preferences for children. If this was true, one should expect to find no evidence of such preferences in countries with a high level of gender equality. In this paper we exploit population register data...

Dieser Beitrag beschäftigt sich mit der Geburtenentwicklung in den nordischen Ländern seit den 1970er Jahren und den Wirkungen familienpolitischer Maßnahmen auf die Fertilitätsentwicklung. Basis der Analysen bilden Auswertungen harmonisierter Registerdaten Dänemarks, Finnlands, Norwegens...

This study examines fertility variation across housing types and childbearing patterns after housing changes. While the effect of family changes on housing choices has been studied in detail, little is known about childbearing patterns within various housing types, despite the fact that many...

A bivariate competing risks problem is considered for a rather general class of survival models. The lifetime distribution of each component is indexed by a frailty parameter. Under the assumption of conditional independence of components the correlated frailty model is considered. The explicit...

There is a growing body of literature looking at the interplay between an individual’s residential and other careers in the life-course. Previous research has mostly studied the impact of partnership and employment changes on spatial mobility. This paper focuses on the effect of childbearing...

We investigate the hypothesis that the propensity of a stepfamily couple to have a shared child is inversely related to the responsibility for rearing pre-union children. We compare effects of coresident pre-union children to those of nonresident, and effects of the woman’s children to those...

Burn-in is a widely used engineering method which is adopted to eliminate defective items before they are shipped to customers or put into the field operation. In the studies of burn-in, the assumption of bathtub shaped failure rate function is usually employed and optimal burn-in procedures are...

Mixtures of distributions are usually effectively used for modeling heterogeneity. It is well known that mixtures of DFR distributions are always DFR. On the other hand, mixtures of IFR distributions can decrease, at least in some intervals of time. As IFR distributions often model lifetimes...

An impact of environment on mortality, similar to survival analysis, is often modeled by the proportional hazards model, which assumes the corresponding comparison with a baseline environment. This model describes the memory-less property, when the mortality rate at a given instant of time...