Survey return rates for multiple-authored versus single-authored covering letters.

Summary Differences in response rates to a three-wave mail survey were assessed when the covering letters were signed by three versus one researcher. 375 surveys including covering letters signed by three researchers and 375 surveys including covering letters signed by one researcher were sent. A follow-up mailing was used to increase the response rate. 199 surveys were returned (53.5%) in which the covering letter had three researchers, and 218 when the covering letter had one researcher (58.7%), not a significantly different distribution.