Respondent Behavior in Panel Studies

Abstract
Many validation studies deal with item nonresponse and measurement error in earnings data. In this article, the author explores respondents’ motives for failing to reveal earnings using the German Socio-Economic Panel (SOEP). The SOEP collects socioeconomic information from private households in the Federal Republic of Germany. The author explains the evolution of income nonresponse in the SOEP and demonstrates the importance of discriminating between refusing to state income and responses of “don’t know.”