Are Advance Postcards or Letters Better? An Experiment with Advance Mailing Types

Busy survey shops struggle daily to figure out the most methodologically sound approach that fits within clients ’ (often limited) budgets. Many projects require innovative techniques even with basic practices, such as advance notification. Sending advance (or prenotification) letters prior to a call or survey helps to increase response rates (De Leeuw et al. 2007; Dillman et al. 1976), but does the type of mailing matter as well? In this article, I compare the results of an advance postcard versus an advance letter, and find that overall letters are the more cost-effective option. Hembroff et al. (2005) established that the format of advance notification (letter versus postcard) matters insofar as advance letters tend to increase response rates more than advance postcards, which in turn reduces the overall survey costs. Obtaining a higher response rate is a desired outcome of most survey research projects because of concern with nonresponse (Groves 2006). Even if both types of advance mailings increase the overall response rate, if there is differential response by subgroups, then this raises concerns abou