Use of a Reimbursement to Increase the Proportion of Prepaid Cellphone Respondents
Marcus E. Berzofsky
RTI International
Kimberly C. Peterson
RTI International
Bo Lu
Division of Biostatistics, Ohio State University
Howard Speizer
RTI International
Timothy Sahr
Ohio Colleges of Medicine Government Resource Center
Prepaid, or pay-as-you-go, cellphone plans are a popular option for many cellphone users. In 2012 an estimated 30% of the cellphone users are using month-to-month type plans that cap the number of airtime minutes allowed or charge for each minute used. Because these alternative plans cost a person plan minutes for both incoming and outgoing calls, persons on these plans may be less likely to participate in a survey. Excluding persons on these alternative plan types may introduce bias in survey estimates intended to be representative of the entire population. This concern over potential bias by under covering alternative phone plan persons is especially true for the OMAS which is designed to identify low income and Medicaid eligible people in Ohio. While OMAS has not traditionally provided an incentive for their survey, the 2015 pilot study, which included a sample of 18,500 cellphone numbers and resulted in 1,076 cellphone respondents, experimented with a $10 reimbursement. We present the results of a split-sample experiment which tested if such a reimbursement increased participation overall or increased the proportion of respondents that are on alternative cellphone plans.