Like many medical studies, the Berlin Aging Study II (BASE‐II) is based on a non‐random "convenience sample" of self‐recruited participants. To study processes of selectivity in BASE‐II, we used an identical questionnaire to compare BASE‐II with a large, representative reference study,...

With the pilot study Living outside Germany, the longitudinal German Socio-Economic Panel Study (SOEP) ventures into completely uncharted methodological territory by attempting to locate the addresses of former participants in the German household panel study SOEP who have since immigrated...

The Berlin Aging Study II (BASE-II) is a multidisciplinary study that allows for the investigation of how a multitude of health status factors as well as many other social and economic outcomes interplay. The sample consists of 1,600 participants aged 60 to 80, and 600 participants aged 20 to...

Throughout adulthood and old age, levels of well-being appear to remain relatively stable. In this chapter, we argue that focusing on a phase of life during which this positive picture does not necessarily prevail promises to help us better understand between-person disparities in the...