Increasing Incentive Salience: Effects of a Pre-Notification Letter on Nonresponse Follow-Up
Julie C. Linville
RTI International
Matt Jans
UCLA Center for Health Policy Research
David Grant
UCLA Center for Health Policy Research
Michael Bostwick
RTI International
Prenotification letters are often sent before the first household contact in telephone surveys to decrease initial nonresponse, but they may also be effective at increasing response in a nonresponse follow-up (NRFU) phase. Such letters are thought to increase the salience of a change in survey protocol, such as an increased incentive. If a protocol modification is expected to have an effect on response, ensuring its salience is essential (Groves, Singer and Corning 2000). We tested the effect of manipulating incentive salience in a telephone survey within 14 diverse communities across California. At the end of the first phase of data collection, a subsample of nonrespondents was selected for additional follow-up by telephone. A random half of the nonresponse follow-up group received a NRFU prenotification letter informing them of an increased incentive ($40, up from $20) and our upcoming call. Half did not receive a letter, but were called and offered the same increased incentive. Findings suggest that the letter does not improve response or reduce the number of interviewer hours required, but does reduce the number of dials made to cases.