The Effectiveness of Incentives on Completion Rates, Data Quality, and Nonresponse Bias in a Probability-based...

Area of Science:

• Survey methodology
• Social sciences research methods
• Online data collection

Background:

• Increasing survey incentives is known to improve response rates in probability-based, cross-sectional surveys.
• The impact of incentives on the response rates, data quality, and nonresponse bias specifically within web panels remains less understood.
• Web panels are increasingly used for research, making the optimization of their response rates crucial.

Purpose of the Study:

• To investigate the effect of larger, postpaid incentives on response rates in a web panel setting.
• To evaluate the impact of increased incentives on data quality within the panel.
• To determine if larger incentives influence nonresponse bias in web panel surveys.

Main Methods:

• Analysis of data from the National Internet Flu Survey conducted in 2015 and 2016.
• Utilized GfK KnowledgePanel® as the sampling frame for participants.
• Compared response rates, data quality metrics, and nonresponse bias between a standard incentive group (US$1) and a larger incentive group (US$5).

Main Results:

• A statistically significant increase in interview completion rates was observed with the larger, 5,000-point (US$5) incentive compared to the standard 1,000-point (US$1) incentive.
• The enhanced incentive had a minimal impact on key data quality indicators.
• No significant increase in nonresponse bias was detected when comparing the two incentive levels.

Conclusions:

• Larger, postpaid incentives are effective in increasing response rates for probability-based web panel surveys.
• The findings suggest that increasing incentives in web panels can be a viable strategy without compromising data integrity or introducing bias.
• This research provides valuable insights for optimizing survey design and maximizing participation in online panels.