The Role of Letters in Graduate Surveys in the Digital Era

Digitalisation has transformed communication and survey research. A high share of the population is Internet literate, and most young adults have access to digital devices. Consequently, postal communication has plummeted. This paper reports from a large-scale experiment where sample members in a graduate survey were randomised into three treatments: a letter reminder (N = 1000), an email reminder (N = 1000) or both an email and a letter reminder (N = 7555). The experimental participants were master’s graduates who had not completed the survey after the initial invitation and one reminder. T-test comparisons of the mean response rates across treatment groups show that letter reminders contribute to a somewhat higher response rate; however, the use of letter reminders requires a careful design due to the obstacles associated with responding to a letter. While the cost of each additional respondent is substantial, our results indicate that contact mode may influence nonresponse bias.