TY - JOUR A1 - Bücker, Michael A1 - Krämer, Walter A1 - Arnold, Matthias T1 - A Hausman test for non-ignorability T2 - Economics Letters Y1 - 2012 UR - https://www.hb.fh-muenster.de/opus4/frontdoor/index/index/docId/9158 VL - 114 IS - 1 SP - 23 EP - 25 ER -