First Author:   Michael Stierle International Network for Economic Research info@infer.info   Av. Jean Van Horenbeeck 256 Brussels, 1160, Belgium   ++/32/2/6744109(Phone) ++/32/2/6744109(Fax) http://www.infer-research.net Second Author: Dr. Kai Rommel Brandenburg Technical University Cottbus rommel@tu-cottbus.de   Cottbus, Germany       http://www.infer-research.net