This study constitutes the first longitudinal exploration of consent to link survey and administrative data. It examines variations in consent over time and explores the influence of the respondents' characteristics (both observed and latent) and the impact of the interviewers on consent co-operation. Respondent inclination to consent is modelled as a latent construct. Most respondents behave consistently over time. However, this consistency is not driven by a strong inclination to consent but rather by the circumstances of the respondents at the time of the interview and by the impact of the interviewers themselves. The findings also show that the change in consent behaviour over time is a clear indication that consent should be treated as a dynamic phenomenon at the individual level.