Getting it Right: Estimating the Share of Volunteers in Denmark

Abstract

Abraham, Helms and Presser (2009) demonstrated that people who volunteer are more likely to participate in surveys. The apparent consequence of such a pattern among respondents is that estimates of volunteering could be biased. Surveys with voluntary work as the main topic could be further biased due to the volunteers' interest on this issue compared with non-volunteers. The article uses panel data from Denmark in order to examine the bias due to panel attrition as a special kind of nonresponse bias and its consequences for estimates of volunteering. The results show that panel attrition leads to an overestimation of the share of people who volunteer.