This paper provides details on the sampling design, field results and nonresponse, as well as population adjustments for the 2018 Sample O of the Socio-Economic Panel (SOEP). Sample O refreshes the SOEPCore sample by adding the residents of households in neighborhoods that receive government...

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