Aalen's Linear Model for Sampled Risk Set Data: A Large Sample Study

Borgan and Langholz (1997) describe a method for estimating the parameter functions in Aalen's linear hazard regression model from sampled risk set data. Using a counting process formulation and the martingale central limit theorem, we provide a study of the asymptotic distributional properties of the estimator. The results are applied to study the efficiencies of the nested case-control and counter-matched designs relative to a full cohort analysis.     

Special issue dedicated to Odd O. Aalen

Lifetime Data Analysis -     

Placement characteristics and stability: a longitudinal analysis of Norwegian children in foster homes

This paper investigates how enhanced support for foster parents, such as covering fees and providing consultants and relief, may reduce the number of replacements experienced by children in foster care. It also investigates the extent to which replacements are associated with family (kin) vs. non‐family foster parents, or with legal characteristics of the placement (i.e. forced administrative decisions vs. relief measures agreed upon by the parents). Statistical analyses of administrative data from Norway investigated the longitudinal relationships between these characteristics and the number of replacements at two levels – children (N = 16 109) and municipalities (N = 418) – over 5 years (2007–2011). The results reveal modest associations between enhanced support and fewer replacements; for example, replacement rates are lower for children placed in homes of kin than in non‐family homes. Replacements also tend to be fewer when the placement is forced rather than consensual.     

New evidence about effects of reproductive variables on child mortality in sub-Saharan Africa

There is still considerable uncertainty about how reproductive factors affect child mortality. This study, based on Demographic and Health Survey data from 28 countries in sub-Saharan Africa, shows that mortality is highest for firstborn children with very young mothers. Other children with young mothers, or of high birth order, also experience high mortality. Net of maternal age and birth order, a short preceding birth interval is associated with above average mortality. These patterns change, however, if time-invariant unobserved mother-level characteristics of importance for both mortality and fertility are controlled for in a multilevel–multiprocess model. Most importantly, there are smaller advantages associated with longer birth intervals and being older at first birth. The implications of alternative reproductive ‘strategies’ are discussed, taking into account that if the mother is older at birth, the child will also be born in a later calendar year, when mortality may be lower.     

Public transport and people with impairments – exploring non-use of public transport through the case of Oslo,Norway

abstract

Despite the attention given to universal design in recent years, many people with impairments still refrain from travelling on public transport. This explorative case study, conducted in the greater Oslo region in Norway, aims to add knowledge on why this is so. Findings indicate that insecurity while travelling and expectations of problems along the way are significant barriers. For many it is the sum of all challenges combined, from experience or anticipation that leads to non-use of public transport. The study shows that universal design policy, as of today, does not lead to accessible public transport systems that rendered impairments irrelevant. If society could safeguard the individuals’ travel needs, this might have profound societal repercussions through increased workforce participation and value added in society. Only then can society make the best use of all its inhabitants while championing inclusiveness and equality.     

Likelihood Inference for Unions of Interacting Discs

Abstract. This is probably the first paper which discusses likelihood inference for a random set using a germ‐grain model, where the individual grains are unobservable, edge effects occur and other complications appear. We consider the case where the grains form a disc process modelled by a marked point process, where the germs are the centres and the marks are the associated radii of the discs. We propose to use a recent parametric class of interacting disc process models, where the minimal sufficient statistic depends on various geometric properties of the random set, and the density is specified with respect to a given marked Poisson model (i.e. a Boolean model). We show how edge effects and other complications can be handled by considering a certain conditional likelihood. Our methodology is illustrated by analysing Peter Diggle's heather data set, where we discuss the results of simulation‐based maximum likelihood inference and the effect of specifying different reference Poisson models.     

Populist political right opinions and political trust among Norwegian youth

Recent decades have seen the growth of various strands of right-wing populist political orientations, where populism and critique of immigration policies have been central. These ideological developments have caused concern for the legitimacy of social and political institutions. The question explored in this paper, based on Norwegian survey data, is ‘Which types of right political orientations exist among young people, and how do these political attitudes affect trust in social and political institutions?’ The results reveal the existence of both a populist ‘new right’ political orientation similar to the ideology of the Progress Party and a nativist ideology. The new right orientation contains two sets of variables: (i) economic liberalism/state scepticism and (ii) nationalist values. For trust in political institutions, the emerging picture is complex because the nationalist dimension of both the populist orientation and the nativist ideological orientation implies a high level of trust in political institutions. To the extent the new right political orientations causes mistrust, it seems to come from the liberal economic, anti-statist values included in this ideology. Based on these findings, future researchers should distinguish more clearly between the ideological dimensions going into populist political right orientations and the relationship between attitudes and more practical implications of such ideologies.