Effects of various types of change in shift schedules: A controlled longitudinal study

Abstract

Data from a longitudinal study accompanying changes in shift rotas connected with a shortening of working time in the chemical industry are presented. Altogether 260 subjects forming five experimental groups participated in both the pretest and the posttest. The effects of the change in shift schedules were controlled by the inclusion of five groups in which 139 subjects participated in both tests. Five types of change in shift schedule were investigated. The purpose was to determine to what extent similar, but in some aspects differing, types of change in shift schedule varied from one another in their effects on those involved, and on which factors their attitudes towards the new shift systems depended with regard to various types of schedule change. The effects of a change in shift schedule were tested by means of the 4-group investigation design developed by Solomon (1949). The results confirm that differences in the effects of new shift systems depend on the type of change. Only in three experimental groups were improvements in health and social life observed. One experimental group showed significant signs of deterioration in subjective health. In the analyses of the factors influencing the attitude of the shiftworkers towards the new shift system, differences in the structure of the influencing factors between the experimental groups were observed. The causal analysis was used in order to test how important the factors found in each group were and which of them were dominant. It showed that the most influential factors dominated so much that the disturbances in the less influential ones lost their importance. In spite of the number of indicators analysed regarding their influence on attitude in this study, further important factors seem to exist that have not been analysed here.     

Randomization tests for multiple regression

Four generic means of conducting randomization tests in the context of multiple regression are analysed. Based on their performance in traditional repeated samples, three of these are shown to be inappropriate or applicable only in special circumstances; their shortcomings are illustrated via Monte Carlo studies     

When Precaution Creates Misunderstandings: The Unintended Effects of Precautionary Information on Perceived Risks,the EMF Case

In the past decade, growing public concern about novel technologies with uncertain potential long‐term impacts on the environment and human health has moved risk policies toward a more precautionary approach. Focusing on mobile telephony, the effects of precautionary information on risk perception were analyzed. A pooled multinational experimental study based on a 5 × 2 × 2 factorial design was conducted in nine countries. The first factor refers to whether or not information on different types of precautionary measures was present, the second factor to the framing of the precautionary information, and the third factor to the order in which cell phones and base stations were rated by the study participants. The data analysis on the country level indicates different effects. The main hypothesis that informing about precautionary measures results in increased risk perceptions found only partial support in the data. The effects are weaker, both in terms of the effect size and the frequency of significant effects, across the various precautionary information formats used in the experiment. Nevertheless, our findings do not support the assumption that informing people about implemented precautionary measures will decrease public concerns.     

Demand for health risk reductions: A cross-national comparison between the U.S. and Canada

Using a large stated preference survey conducted across the U.S. and Canada, we assess differences in individual willingness to pay (WTP) for health risk reductions between the two countries. Our utility-theoretic choice model allows for systematically varying marginal utilities for avoided future time in different adverse health states (illness-years, recovered/remission years, and lost life-years). We find significant differences between Canadian and U.S. preferences. WTP also differs systematically with age, gender, education, and marital status, as well as a number of attitudinal and subjective health-perception variables. Age profiles for WTP are markedly different across the two countries. Canadians tend to display flatter age profiles, with peak WTP realized at older ages.     

Estimating the prevalence of sensitive behaviour and cheating with a dual design for direct questioning and randomized response

Randomized response is a misclassification design to estimate the prevalence of sensitive behaviour. Respondents who do not follow the instructions of the design are considered to be cheating. A mixture model is proposed to estimate the prevalence of sensitive behaviour and cheating in the case of a dual sampling scheme with direct questioning and randomized response. The mixing weight is the probability of cheating, where cheating is modelled separately for direct questioning and randomized response. For Bayesian inference, Markov chain Monte Carlo sampling is applied to sample parameter values from the posterior. The model makes it possible to analyse dual sample scheme data in a unified way and to assess cheating for direct questions as well as for randomized response questions. The research is illustrated with randomized response data concerning violations of regulations for social benefit.