Nauwkeurigheid van gerapporteerde giften aan goededoelenorganisaties

Researchers routinely use self-report surveys as sources of data on social phenomena. In the present paper I examine the accuracy of self-reports on charitable donations. I provide a theoretical framework for research on the accuracy of social phenomena and apply this to charitable donations. In the empirical part of the paper, I compare self-reports on household donations to Greenpeace the Netherlands and administrative records on donations received from these households. I find considerable bias in self-reports. Substantial proportions of respondents fail to report donations that have in fact been received by charitable organizations. An almost equal proportion of respondents report donations that have not been received. Among true positives, the amounts reported are somewhat higher than the amounts recorded. As a result, the average bias is close to zero. The accuracy of self-reports is lower among the elderly and among dual earner households. These findings can be explained as a result of memory problems and a lack of information. The accuracy of self-reports is higher among respondents who also report other socially desirable behaviors such as voting and blood donation. These findings suggest that the more civic-minded individuals are more accurate respondents.