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...

A system subject to a point process of shocks is considered. Shocks occur in accordance with a nonhomogeneous Poisson process. Different criterions of system failures are discussed in a homogeneous case. Two natural settings are analyzed. Heterogeneity is modeled by an unobserved univariate...

Interpersonal relationships of support have been found to be an important factor in individual fertility intentions in Central and Eastern European countries. The foundations of this positive influence have not been well explored to date, however. We present a theoretical discussion on...

Models on the impact of social networks on reproductive behavior primarily address processes of interpersonal influence on fertility related values and utility perceptions and consider aspects of social support and social capital only to a small extend. On the basis of an exchange theoretical...

Some stochastic approaches to biological aging modeling are studied. We assume that an organism acquires a random resource at birth. Death occurs when the accumulated dam-age (wear) exceeds this initial value, modeled by the discrete or continuous random vari-ables. Another source of death of an...

Mixtures of increasing failure rate distributions (IFR) can decrease at least in some intervals of time. Usually this property can be observed asymptotically as time tends to infinity. This is due to the fact that the mixture failure rate is ‘bent down’ compared with the corresponding...

If aging is understood as some process of damage accumulation, it does not necessarily lead to increasing mortality rates. Within the framework of a suggested generalization of the Strehler-Mildwan (1960) model, we show that even for models with monotonically increasing degradation, the...

Research about fertility has focused in the main on studying separately the influences of communication networks and social capital on reproductive behavior, but it has rarely tried to integrate both network properties theoretically or analytically. We therefore discuss a general model of...

Personal networks receive increasing recognition as structural determinants of fertility. However, the network perspective also helps to explain personal motivations for having children. Using theories of interpersonal exchange and of the value of children, it is argued that children can...

Statistical analysis of data on the longest living humans leaves room for speculation whether the human force of mortality is actually leveling o®. Based on this uncertainty, we study a mixture failure model, introduced by Finkelstein and Esaulova (2006) that generalizes, among others, the...