Incentives are all forms of monetary or non-monetary encouragement given to potential respondents (Singer, 2002; Singer & Ye, 2013). Non-monetary incentives include vouchers, lottery tickets, vouchers for contributions to charity, stamps, and objects. The monetary value of the incentives used in studies ranges from tiny amounts to several hundred euros in the case of medical studies. Moreover, incentives differ in terms of the way in which they are awarded: Pre-paid incentives are provided in advance, irrespective of whether the recipient participates in the overall gross sample. Conditional incentives are given to respondents after they have participated in the survey.
This contribution provides an overview of the current state of theories and empirical findings on the impact on response rates, retention rates and sample quality of giving incentives to respondents.
Pforr, K. (2016). Incentives. GESIS Survey Guidelines. Mannheim, Germany: GESIS – Leibniz Institute for the Social Sciences. DOI: 10.15465/gesis-sg_en_001
Klaus Pforr, Michael Blohm, Annelies G. Blom, Barbara Erdel, Barbara Felderer, Mathis Fräßdorf, Kristin Hajek, Susanne Helmschrott, Corinna Kleinert, Achim Koch, Ulrich Krieger, Martin Kroh, Silke Martin, Denise Saßenroth, Claudia Schmiedeberg, Eva-Maria Trüdinger, Beatrice Rammstedt, Are Incentive Effects on Response Rates and Nonresponse Bias in Large-scale, Face-to-face Surveys Generalizable to Germany? Evidence from Ten Experiments, Public Opinion Quarterly, Volume 79, Issue 3, Fall 2015, Pages 740–768, https://doi.org/10.1093/poq/nfv014