Juan Enrique Martinez-Legaz Universitat Autonoma de Barcelona   Departament d''Economia i d''Historia Economica Universitat Autonoma de Barcelona Bellaterra, 08193 Spain   JuanEnrique.Martinez@uab.es   http://hotelling.uab.es/jml/jeml.html       Primary Research Focus: Mathematical Economics   JEL Areas: C6 : Mathematical Methods and Programming: General C0 : Mathematical and Quantitative Methods: General