Panel survey participation can bring about unintended changes in respondents' behavior and/or reporting of behavior. Using administrative data linked to a large panel survey, we analyze changes in respondents' labor market behavior. We estimate the causal effect of panel participation on the take-up of federal labor market programs using instrumental variables. Results show that panel survey participation leads to a decrease in respondents' take-up of these measures. These results suggest that panel survey participation not only affects the reporting of behavior, as previous studies have demonstrated, but can also alter respondents' actual behavior.