Replication Data for: The effect of advance letters on survey participation: The case of Ireland and the European Social Survey

This study examined the effects of advance letters on individual participation in the 2018 round of the European Social Survey in Ireland. As participation rates in household surveys have been in decline in many countries, understanding the impact of engagement strategies, such as prior contact, are crucial for fieldwork planning and overall quality of data collection. Based on a natural experiment, we assessed the likelihood of individuals to take part in the survey comparing those who have received an advance letter with those who did not receive it. Contrary to previous evidence on the effectiveness of prior contact, our results indicate that individuals in the sample that received an advance letter are less likely to take part in the survey. We discuss these results in light of an increasing public scepticism regarding social surveys and data privacy.