Summary. Panel survey participation can bring about unintended changes in respondents' behaviour and/or their reporting of behaviour. Using administrative data linked to a large panel survey, we analyse whether the survey brings about changes in respondents' labour market behaviour. We estimate the causal effect of panel participation on the take-up of federal labour market programmes by using instrumental variables. Results show that panel survey participation leads to an increase in respondents' take-up of these measures. These results suggest that panel survey participation not only affects the reporting of behaviour, as previous studies have demonstrated, but can also alter respondents' actual behaviour.Keywords: Administrative data; Instrumental variable; Longitudinal data; Panel conditioning; Treatment effects
BackgroundPanel surveys are a key resource for researchers and policy makers who seek to understand dynamic processes, such as movements in and out of the labour force. Yet such surveys are also vulnerable to the critique that participation can distort respondents' behaviour and/or responses, making the collected data unrepresentative of the larger population. This phenomenon is referred to as panel conditioning (Halpern-Manners et al., 2017). Although concerns about panel conditioning first arose in the 1940s (Lazarsfeld, 1940), researchers from many disciplines still rely on panel data for causal analysis. In this study, we test whether participation in the large-scale German panel study 'Labour market and social security' alters respondents' labour market behaviour. We think of participation in any of the first three waves of the panel survey as a treatment and the panel conditioning effect as a treatment effect. The outcome variables of interest are take-up of federal labour market programmes and job search behaviour, i.e. we use techniques of causal analysis to study whether panel survey participation makes respondents more or less likely to take part in the labour market programmes and whether it helps respondents to find a job faster.Our study faces two major methodological challenges. First, we need to disentangle the effect of survey participation on changes in behaviour from changes in reporting. Administrative labour market data, which are independent of respondents' reporting, make this disentangle-