Institute for Social and Economic Research The Institute for Social and Economic Research ( ISER ) specialises in the production and analysis of longitudinal data . ISER incorporates the following centres

This paper explores the relationship between the day of the week on which a survey respondent is interviewed and their self-reported job satisfaction and mental health scores using from the first ten years of the British Household Panel Survey. Evidence presented here confirms that self-reported levels of job satisfaction and subjective levels of mental distress systematically vary according to the day of the week on which respondents are interviewed even when controlling for other observed and unobserved characteristics. Other previously ignored factors that have important impacts on mental distress and job satisfaction emerge from our analysis. NON-TECHNICAL SUMMARY Economic research into well-being, mental health and job satisfaction has proliferated in recent years in attempts to discover the levels and sources of peoples’ general happiness. Most studies deal with self-reported, subjective measures at the individual level. It is argued that such data approximate the theoretical concept of utility and are therefore worthy of investigation. However, it is important to explore how sensitive such measures are to calendar effects, such as day of the week on which an interview takes place. Do employees systematically report being less satisfied in their job at the beginning of the week than at the end of the week? Do they report different levels of mental well-being at the start of the working week than at the end of the week? If so, this has important implications for the accuracy and reliability of such well-being data, and for the conclusions drawn from their analyses. In this paper, we examine the importance of the day of the week on which a survey respondent is interviewed in determining their reported levels of mental well-being and job satisfaction using British panel data for the 1990s. We also highlight other previously ignored determinants of job satisfaction and mental well-being. Our results confirm that self-reported levels of job satisfaction and levels of mental distress systematically vary according to the day of the week on which respondents are interviewed. These day of interview effects are particularly pronounced for levels of mental distress among women, and emerge even when holding a wide range of individual, household, and job related characteristics constant, and eliminating any unobserved time invariant, individual specific effects. In particular, our results suggest that men and women interviewed on Friday report higher levels of job satisfaction and lower levels of mental stress than those interviewed in the middle of the week. As well as providing important evidence on the psychological well being of individuals and how this varies through the week, these results suggest that any analyses of job satisfaction or subjective well-being which do not explicitly allow for such effects should be treated with caution. While a comparison of our results with previous findings suggests that the main conclusions are robust to the inclusion of the day of interview controls, we highlight other important determinants of job satisfaction and subjective well-being that have not previously been identified in the literature. In particular, our results suggest that over-employment has the largest negative effect on job satisfaction among both male and female workers in Britain, while a deteriorating financial situation has a large negative impact on mental well-being. Therefore financial hardship has both psychological and material consequences for individuals.