A new nonlinear asymmetric cointegration approach using error correction models

In this article, two new powerful tests for cointegration are proposed. The general idea is based on an intuitively appealing extension of the traditional, rather restrictive cointegration concept. In this article, we allow for a nonlinear, but most importantly a different, asymmetric convergence process to account for negative and positive changes in our cointegration approach. Using Monte Carlo simulations we verify, that the estimated size of the first test depends on the unknown value of a signal-to-noise ratio q. However, our second test—which is based on the original ideas of Kanioura and Turner—is more successful and robust in the sense that it works in all of the different evaluated situations. Furthermore it is shown to be more powerful than the traditional residual based Enders and Siklos method. The new optimal test is also applied in an empirical example in order to test for potential nonlinear asymmetric price transmission effects on the Swedish power market. We find that there is a higher propensity for power retailers to rapidly and systematically increase their retail electricity prices subsequent to increases in Nordpool's wholesale prices, than there is for them to reduce their prices subsequent to a drop in wholesale spot prices.     

Prior specification of neighbourhood and interaction structure in binary Markov random fields

We formulate a prior distribution for the energy function of stationary binary Markov random fields (MRFs) defined on a rectangular lattice. In the prior we assign distributions to all parts of the energy function. In particular we define priors for the neighbourhood structure of the MRF, what interactions to include in the model, and for potential values. We define a reversible jump Markov chain Monte Carlo (RJMCMC) procedure to simulate from the corresponding posterior distribution when conditioned to an observed scene. Thereby we are able to learn both the neighbourhood structure and the parametric form of the MRF from the observed scene. We circumvent evaluations of the intractable normalising constant of the MRF when running the RJMCMC algorithm by adopting a previously defined approximate auxiliary variable algorithm. We demonstrate the usefulness of our prior in two simulation examples and one real data example.     

The Gender Revolution: A Framework for Understanding Changing Family and Demographic Behavior

This article argues that the trends normally linked with the second demographic transition (SDT) may be reversed as the gender revolution enters its second half by including men more centrally in the family. We develop a theoretical argument about the emerging consequences of this stage of the gender revolution and review research results that bear on it. The argument compares the determinants and consequences of recent family trends in industrialized societies provided by two narratives: the SDT and the gender revolution in the public and private spheres. Our argument examines differences in theoretical foundations and positive vs. negative implications for the future. We focus primarily on the growing evidence for turnarounds in the relationships between measures of women's human capital and union formation, fertility, and union dissolution, and consider evidence that men's home involvement increases union formation and fertility and decreases union instability. Although the family trends underlying the SDT and the gender revolution narratives are ongoing and a convincing view of the phenomenon has not yet emerged, the wide range of recent research results documenting changing, even reversing relationships suggests that the gender approach is increasingly the more fruitful one.     

Geometric Anisotropic Spatial Point Pattern Analysis and Cox Processes

We consider spatial point processes with a pair correlation function, which depends only on the lag vector between a pair of points. Our interest is in statistical models with a special kind of ‘structured’ anisotropy: the pair correlation function is geometric anisotropic if it is elliptical but not spherical. In particular, we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial point patterns.     

The Relationship Between Aversive Conditioning and Risk-avoidance in Gambling

This study investigated the relationship between aversive conditioning, heart rate variability suppression, behavioral activation system/behavioral inhibition system and risk-avoidance on the Iowa gambling task (IGT) in a nonclinical sample (29 male, 29 female, mean age = 20.7). A laboratory based Pavlovian aversive conditioning paradigm was used where a 1500 Hz tone (CS+) was followed by a burst of loud white noise (US), and a 850 Hz (CS−) tone was never followed by the US. In a subsequent extinction phase where the CS+ and CS− were presented without the US, conditioned skin conductance responses to the CS+ indicated aversive conditioning. The results showed that the participants who did not show aversive conditioning (N = 26) exhibited significantly less risk-avoidance compared to participants who did show aversive conditioning (N = 32). Regression analysis showed that among the study variables, only aversive conditioning contributed significantly to explaining variance in risk-avoidance. These results may have implications for understanding risk-taking in gambling in general, and may be a starting point understanding the role of aversive conditioning in the development and maintenance of gambling problems.     

A time-varying measurement error model for age of onset of a psychiatric diagnosis: applied to first depressive episode diagnosed by the Composite International Diagnostic Interview (CIDI)

A substantial degree of uncertainty exists surrounding the reconstruction of events based on memory recall. This form of measurement error affects the performance of structured interviews such as the Composite International Diagnostic Interview (CIDI), an important tool to assess mental health in the community. Measurement error probably explains the discrepancy in estimates between longitudinal studies with repeated assessments (the gold-standard), yielding approximately constant rates of depression, versus cross-sectional studies which often find increasing rates closer in time to the interview. Repeated assessments of current status (or recent history) are more reliable than reconstruction of a person's psychiatric history based on a single interview. In this paper, we demonstrate a method of estimating a time-varying measurement error distribution in the age of onset of an initial depressive episode, as diagnosed by the CIDI, based on an assumption regarding age-specific incidence rates. High-dimensional non-parametric estimation is achieved by the EM-algorithm with smoothing. The method is applied to data from a Norwegian mental health survey in 2000. The measurement error distribution changes dramatically from 1980 to 2000, with increasing variance and greater bias further away in time from the interview. Some influence of the measurement error on already published results is found.     

Why Wait ‘til Marriage? The Determinants of Premarital Sex among Adolescents in a Country in Sub-Saharan Africa: Botswana

The purpose of the study was to describe the premarital sexual behaviors of Botswana adolescents and examine the factors associated with premarital sex intentions. An anonymous self-reported questionnaire was administered to 1,054 pupils ages 10 to 18 years in school and out of school. The findings indicate that the theory of planned behavior provides a model for developing interventions to reduce the risk behavior in regard to HIV/AIDS through premarital sex. The findings in the study indicate factors that influence adolescent intentions to engage in premarital sexual intercourse and the need to address these when designing effective interventions.     

A model for publishing a hypertext journal

Abstract

We dedicate this first issue of 2002 to Cindy Hepfer and share a few well-chosen words to honor her for her years of editorial leadership. Serials Review 2002; 28:1–3.     

Attentional Bias in Problem Gambling: A Systematic Review

Attentional bias has been the subject of extensive empirical investigation in connection with chemical addictions, and it has been demonstrated in users of several different substances. The findings show that substance users seem to notice and attend to substance-related stimuli more readily than non-substance-related stimuli. Less is known, however, about attentional bias in pathological gambling. This systematic review investigates the existing empirical evidence on attentional bias in problem and pathological gamblers. Eleven studies were identified and evaluated following a literature search. Key findings are that problem and pathological gamblers seem to exhibit attentional bias toward gambling-related stimuli across different measuring paradigms, although some negative findings were reported. Recommendations aimed at improving research on this topic include better validation of measures, the inclusion of manipulations of craving level, and adding variations in gambling severity as a variable, as well as gambling preference. Research on therapeutic procedures aimed at reducing attentional bias is also recommended.