the interview mode, item-nonresponse and representativeness of the sample used, one should also consider the following study: Börsch-Supan, A., M. Coppola, L. Essig, A. Eymann, D. Schunk (2008): The German SAVE study. Design and Results. MEA Study Nr. 6, MEA Mannheim. Artikel Ziegelmeyer, Michael (2012): „Illuminate the unknown: Evaluation of imputation procedures based on the SAVE Survey”, Advances in Statistical Analysis, Busl, Claudia; Iliewa, Zwetelina; Jokisch, Sabine; Kappler, Marcus; Roscher, Thomas; Schindler, Felix; Schleer, Frauke (2012): “Sparen und Investieren vor dem Hintergrund des demografischen Wandels” Report for the German Federal Ministry of Finance, Berlin. References External links http://www.mea.mpisoc.mpg.de/index.php?id=315&L=2 https://web.archive.org/web/20110717064418/http://www.tns-infratest-sofo.com/arbeitsber/2550/2550_kurzf1.html Personal finance