Linking data from longitudinal surveys to administrative records (whether held by government or private entities) is an increasingly attractive option for several reasons. As longitudinal surveys continue to respond to pressures to increase efficiency, and as new survey modes are developed, the use of mixed-mode data collection is increasing. Much of the work on informed consent for administrative data linkages has focused on exploring correlates of consent at both the respondent and interviewer level and examining non-consent bias. In this chapter, the authors focus on understanding the process by which respondents decide whether to give consent. They use both quantitative analyses of existing data from Understanding Society and qualitative work to explore the consent process. The quantitative analyses document the extent to which respondents make consistent decisions, and the extent to which the mode of data collection affects this decision, by addressing some research questions.
