Irenaeus Wolff, Journal of Economic Psychology, 74: 102197, 2019

  • Paying participants as soon as they finish the questionnaire ruins the data quality.
  • If data quality is key, wait until everybody has finished before starting to pay. This often is costly, of course. If data quality is not absolutely key, consider paying after most participants have finished the questionnaire.
  • Paying too little overall is bad too. Framing the show-up fee as being „for the completion of the questionnaire“ doesn‘t help, though.
  • Neither providing progress feedback nor having people put in their names to prepare the receipts seems to affect the data quality. In our case, asking people to enter their names does not lead to more socially-desirable answers even on the very next screen, while providing progress feedback after two thirds of the pages at least improves the motivation to fill in open-answer questions.