Dissatisfied with life or with being interviewed? : Happiness and the motivation to participate in a survey

Abstract

People with little motivation to participate in surveys can affect empirical research when they abstain from but also when they actually participate in interviews. This paper investigates whether happiness data are susceptible to such measurement bias. Evidence from the German Socio-Economic Panel Study (SOEP) reveals a strong relationship between self-reported life satisfaction and several indicators of respondent motivation, such as subsequent panel attrition. One explanation for this finding is that respondents on the margin of participation truly have lower life satisfaction. Alternatively, their low motivation may be the cause for an underreporting of life satisfaction. To learn more about this, an instrumental variable approach identifies future panel quitters with low motivation by using the occurrence of interviewer attrition in the year after the interview. The results of this analysis suggest that self-reported life satisfaction declines because of low respondent motivation. A discussion of the implications for analyses of happiness data underscores the potential importance of respondent motivation regardless of the explanation for why interviewees with low motivation report lower life satisfaction.