This paper builds on prior research on alternative protocols for conducting mixed-mode surveys by mail where respondents are asked to complete either a web questionnaire or a paper questionnaire. We present the results from a 4 × 2 factorial experiment in which the first factor, the survey protocol, varied the modes initially offered (either web alone or both web and paper) as well as the order in which they are offered in subsequent follow-up contacts (either concurrently or sequentially). This factor was crossed with a second factor offering various promised incentive amounts and response options (a $5 prepaid incentive with a promise of either $10 or $20 for response). Our research sought to evaluate the differences between protocols/incentive treatments relative to their costs, response rates, respondent choice of web versus paper response, and consistency with benchmark estimates in other large-scale surveys. Specifically, we introduce a new protocol referred to as choice+ (i.e., choice plus) that presents both web and paper response options concurrently at the initial request, but promises a bonus ($10) incentive for choosing the web option. Results presented are from the 2015 Residential Energy Consumption Survey National Pilot study—an experimental component of the main Residential Energy Consumption Survey sponsored by the U.S. Energy Information Administration.
Using bonus monetary incentives to encourage web response in mixed-mode household surveys