Patterns of working and living conditions: a holistic, multivariate approach to occupational health studies

The objective of the study was to develop a multivariate approach to occupational health studies that is: capable of identifying groups with similar working conditions; relevant for studies of associations between working and living conditions and health; and an appropriate basis for preventive actions. Data at the individual level were obtained through measurements, observations, interviews and questionnaires, and at the organizational level, through interviews with managers. Cluster analyses were applied with the purpose of identifying groups of individuals with small, within-group differences. Eighty work sites and a sample of employees at each site were strategically selected. The study group comprised 203 men and women, and was characterized by large variation. The final analysis produced eight clusters of individuals, denoted according to their best-defining characteristic, i.e. 'decent', 'boundary-less', 'locked', 'exposed', 'heavy and monotonous', 'changed', 'mobile' and 'restrained'. The clusters differed with regard to 'what' characterized working conditions, 'where' on the labour market they were found, and 'who' clustered in these groups. The holistic approach revealed conditions that were important for health and had higher explanatory power in relation to ill-health than applying socio-economic groupings or the demand-control-support model. It showed how psychosocial, ergonomic-physical and occupational hygiene factors combine and interact to create settings with different risks of ill-health. The chosen strategy is recommended for future occupational health studies and is particularly suitable as guidance for preventive actions relevant to specific clusters of working and living conditions.     

On the Asymptotic Sizes of Subset Anderson–Rubin and Lagrange Multiplier Tests in Linear Instrumental Variables Regression

We consider tests of a simple null hypothesis on a subset of the coefficients of the exogenous and endogenous regressors in a single‐equation linear instrumental variables regression model with potentially weak identification. Existing methods of subset inference (i) rely on the assumption that the parameters not under test are strongly identified, or (ii) are based on projection‐type arguments. We show that, under homoskedasticity, the subset Anderson and Rubin (1949) test that replaces unknown parameters by limited information maximum likelihood estimates has correct asymptotic size without imposing additional identification assumptions, but that the corresponding subset Lagrange multiplier test is size distorted asymptotically.     

Finite Sample Properties of the Two-Step Empirical Likelihood Estimator

ABSTRACT

We investigate the finite sample properties of two-step empirical likelihood (EL) estimators. These estimators are shown to have the same third-order bias properties as EL itself. The Monte Carlo study provides evidence that (i) higher order asymptotics fails to provide a good approximation in the sense that the bias of the two-step EL estimators can be substantial and sensitive to the number of moment restrictions and (ii) the two-step EL estimators may have heavy tails.     

Genetic and environmental effects on sexual excitation and sexual inhibition in men

The Sexual Inhibition and Sexual Excitation Scales (SIS/SES) measure the propensity for sexual inhibition and excitation in men. According to the theoretical model underlying the SIS/SES, sexual response and associated behavior depend on dual control mechanisms in the brain involving the balance of excitatory and inhibitory systems which impinge on sexual response. Previous research with the SIS/SES has indicated one higher-order excitatory factor and two higher-order inhibitory factors affecting sexual response. The present study analyzed the item structure and the psychometric properties of the instrument in a population based sample of Finnish male twins (N = 1,289), and, including 37 out of 45 items of the original scales, estimated the heritability of and the environmental influences on the excitatory and inhibitory mechanisms. The twin correlations and the structural equation modeling suggested modest heritability for both inhibitory mechanisms. Sexual excitation, in contrast, was not influenced by genetic effects and similarities between twins for this mechanism seemed to be caused by the common environment of the twins.