The German Socio-Economic Panel Study (SOEP) is a multidisciplinary household panel study that covers a wide range of social and behavioral sciences, including economics, sociology, psychology, survey methodology, econometrics, educational science, political science, public health, behavioral genetics, demography, geography, and sport science. The study aims to provide longitudinal data on living conditions and a multitude of variables from the social sciences for both theoretical investigation and policy evaluation. SOEP has evolved over the years, enhancing its representativeness and analytical power through various improvements, such as expanding the sample size, oversampling specific groups, and introducing new data collection methods. The study has also broadened its scope by incorporating more psychological and behavioral concepts into its questionnaire, including health measures, physical health indicators, and personal trait assessments. SOEP's unique design, which follows all members of the first-wave survey households and their offspring over time, allows for detailed analysis of intergenerational transmissions and life course outcomes. The paper discusses the current theoretical and empirical developments that highlight the need for multidisciplinary longitudinal data, and it concludes with a discussion of potential future issues and developments for SOEP and other household panel studies.The German Socio-Economic Panel Study (SOEP) is a multidisciplinary household panel study that covers a wide range of social and behavioral sciences, including economics, sociology, psychology, survey methodology, econometrics, educational science, political science, public health, behavioral genetics, demography, geography, and sport science. The study aims to provide longitudinal data on living conditions and a multitude of variables from the social sciences for both theoretical investigation and policy evaluation. SOEP has evolved over the years, enhancing its representativeness and analytical power through various improvements, such as expanding the sample size, oversampling specific groups, and introducing new data collection methods. The study has also broadened its scope by incorporating more psychological and behavioral concepts into its questionnaire, including health measures, physical health indicators, and personal trait assessments. SOEP's unique design, which follows all members of the first-wave survey households and their offspring over time, allows for detailed analysis of intergenerational transmissions and life course outcomes. The paper discusses the current theoretical and empirical developments that highlight the need for multidisciplinary longitudinal data, and it concludes with a discussion of potential future issues and developments for SOEP and other household panel studies.