Advance letters (ALs) are one tool for improving response rates. However, it is not sufficiently clear whether ALs affect nonresponse bias, and how their effect relates to the study topic. (1) The effect of ALs on outcome rates, (2) recruitment effort, (3) their differential effect on subgroups, and (4) their effect on reporting on sensitive topics are examined. The data stem from a split-ballot experiment implemented in ax telephone survey on “Violence against Men.” The study comprises responses from approximately 950 men aged 21–70 years. The results indicate a positive effect of ALs on response, cooperation, and contact rates, and higher response rates among older respondents. Self-reports on sensitive topics were not affected by the ALs.
Read the recently published paper in the International Journal of Public Opinion Reserach.