Tests for time series of counts based on the probability-generating function

We propose testing procedures for the hypothesis that a given set of discrete observations may be formulated as a particular time series of counts with a specific conditional law. The new test statistics incorporate the empirical probability-generating function computed from the observations. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is included as well as real-data examples.     

An individual measure of relative survival

Summary.  Relative survival techniques are used to compare survival experience in a study cohort with that expected if background population rates apply. The techniques are especially useful when cause-specific death information is not accurate or not available as they provide a measure of excess mortality in a group of patients with a certain disease. Whereas these methods are based on group comparisons, we present here a transformation approach which instead gives for each individual an outcome measure relative to the appropriate background population. The new outcome measure is easily interpreted and can be analysed by using standard survival analysis techniques. It provides additional information on relative survival and gives new options in regression analysis. For example, one can estimate the proportion of patients who survived longer than a given percentile of the respective general population or compare survival experience of individuals while accounting for the population differences. The regression models for the new outcome measure are different from existing models, thus providing new possibilities in analysing relative survival data. One distinctive feature of our approach is that we adjust for expected survival before modelling. The paper is motivated by a study into the survival of patients after acute myocardial infarction.     

Tests for Structural Changes in Time Series of Counts

We propose methods for detecting structural changes in time series with discrete‐valued observations. The detector statistics come in familiar L2‐type formulations incorporating the empirical probability generating function. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. For both models, we study mainly structural changes due to a change in distribution, but we also comment for the classical problem of parameter change. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is also included along with a real data example.     

Housing of Seniors in the Czech Republic: Challenges for Social Services

The article focuses on the housing market, the behavior and motivations of senior households to move or to stay in place. Knowing if and why seniors decide to move at retirement is a critical factor for the establishment of social service policies in terms of their structure, location, and provision.

This study uses secondary data based on information about Czech households collected by the Czech Statistical Office (CSO). The data are annually collected via sample surveys of the income and living conditions of households (EU-SILC). The sample covers more than eight thousands of households. Analyzed data cover the period 2007–2012 when the abolishment of rent regulation in the Czech Republic took place. It is hypothesized that an impact like this might increase the willingness to move and reveal the factors which underlie the decisions of particular households.

The results indicated that most Czech households that decided to move during the study period were driven by the increased financial burden of housing. Other factors, including the availability of social services and public utilities within the current location, played only minor roles. It seems that Czech senior households act in a very pragmatic and rational manner when deciding whether to stay in place or move, with the majority of households preferring not to move. Social policies should, therefore, concentrate on providing services for the current locations rather than on the construction of new social housing.     

Prediction of posttraumatic stress disorder symptomatology after childbirth – A Croatian longitudinal study

Background

Following childbirth, a vast number of women experience some degree of mood swings, while some experience symptoms of postpartum posttraumatic stress disorder.

Limited Role of Body Satisfaction and Body Image Self-Consciousness in Sexual Frequency and Satisfaction in Pregnant Women

This cross-sectional study examined the role of maternal body image and body image self-consciousness in sexual satisfaction and intercourse frequency during pregnancy when controlling for satisfaction with partnership. Pregnant women in their third trimester of pregnancy (N = 150) participated in the study. Body image was measured by the Body Areas Satisfaction Scale (BASS) and Body Image Self-Consciousness Scale (BISC), while relationship satisfaction was measured by different subscales of the Perceived Quality of Marital Relationship (PQMR) Scale. Sexual satisfaction was also measured by one of the subscales of the PQMR (Intimate Relationship). The sexual behavior questionnaire comprised questions about frequency of sexual intercourse, desire, and other aspects of sexual functioning as well as the reasons that might prevent women from having intercourse during pregnancy. Findings suggested that satisfaction with body image and body image self-consciousness were related to sexual satisfaction. Nevertheless, other aspects of partnership, such as communication, appeared to be much more important predictors of sexual satisfaction than body image variables. The best predictor of sexual frequency was fear that intercourse might harm the fetus. Implications for education about sexuality issues in pregnancy are discussed.     

Is High Sexual Desire a Risk for Women’s Relationship and Sexual Well-Being?

Historically, women’s sexual desire has been deemed socially problematic. The growing popularity of the concept of hypersexuality—which lists high sexual desire among its core components—poses a risk of re-pathologizing female sexual desire. Data from a 2014 online survey of 2,599 Croatian women aged 18–60 years was used to examine whether high sexual desire is detrimental to women’s relationship and sexual well-being. Based on the highest scores on an indicator of sexual desire, 178 women were classified in the high sexual desire (HSD) group; women who scored higher than one standard deviation above the Hypersexual Disorder Screening Inventory mean were categorized in the hypersexuality (HYP) group (n = 239). Fifty-seven women met the classification criteria for both groups (HYP&HSD). Compared to other groups, the HSD was the most sexually active group. Compared to controls, the HYP and HYP&HSD groups—but not the HSD group—reported significantly more negative consequences associated with their sexuality. Compared to the HYP group, women with HSD reported better sexual function, higher sexual satisfaction, and lower odds of negative behavioral consequences. The findings suggest that, at least among women, hypersexuality should not be conflated with high sexual desire and frequent sexual activity.     

A comparison of L-, LQ-, TL-moment and maximum likelihood high quantile estimates of the GPD and GEV distribution

In this article, L-moments, LQ-moments and TL-moments of the generalized Pareto and generalized extreme-value distributions are derived up to the fourth order. The first three L-, LQ- and TL-moments are used to obtain estimators of their parameters. Performing a simulation study, high-quantile estimates based on L-, LQ-, and TL-moments are compared to the maximum likelihood estimate with respect to their sample mean squared error. This consists of identifying an optimal combination of parameters α and p both considered in the range [0, 0.5] for estimating quantiles by LQ-moments. The results show L-moment and maximum likelihood methods outperform other methods.     

Adaptive multiple importance sampling for Gaussian processes

In applications of Gaussian processes (GPs) where quantification of uncertainty is a strict requirement, it is necessary to accurately characterize the posterior distribution over Gaussian process covariance parameters. This is normally done by means of standard Markov chain Monte Carlo (MCMC) algorithms, which require repeated expensive calculations involving the marginal likelihood. Motivated by the desire to avoid the inefficiencies of MCMC algorithms rejecting a considerable amount of expensive proposals, this paper develops an alternative inference framework based on adaptive multiple importance sampling (AMIS). In particular, this paper studies the application of AMIS for GPs in the case of a Gaussian likelihood, and proposes a novel pseudo-marginal-based AMIS algorithm for non-Gaussian likelihoods, where the marginal likelihood is unbiasedly estimated. The results suggest that the proposed framework outperforms MCMC-based inference of covariance parameters in a wide range of scenarios.     

Did Wars Make Nation‐States in the Balkans?: Nationalisms,Wars and States in the 19th and early 20th Century South East Europe

Nationalism and protracted warfare are often seen as the most important impediments to social advancement in the Balkans. In contrast to these popular perceptions I argue that for much of its history the Balkan region was characterised by limited inter‐state violence and by notable lack of nationalist ideologies. Furthermore by comparing the processes of state and nation formation and warfare in the South East Europe with those in the Western Europe the article aims to show that it is the weakness, not the strength, of nationalism and protracted warfare that historically have been the principal obstacles for social development. The general argument of the paper is developed in dialogue with Tilly's theory that ties state formation to proliferation of wars and Gellner's model that links the rise of nationalism to emergence of standardised educational systems and industrialisation. In an attempt to partially disprove Tilly and vindicate Gellner I argue that the experience of the Balkan region indicates that although wars can prove important catalysts of state formation they may not necessarily contribute to nation formation.