Helge Sanner University of Potsdam   Lehrstuhl für Volkswirtschaftslehre, Wirtschaftstheorie Karl-Marx-Str. 67 Potsdam, 14482 Germany   sanner@rz.uni-potsdam.de     Biographical Sketch: University degree (Diplom-Volkswirt) 1996 from University of Kiel, Dr. rer. pol. 2001 from University of Potsdam, current position: assistent professor, University of Potsdam       JEL Areas: R3 : Production Analysis and Firm Location: General L1 : Market Structure, Firm Strategy, and Market Performance: General