First Author:   Sumru Altug University of York and CEPR sga1@york.ac.uk   Department of Economics and Related Studies, Heslington York, YO10 5DD, UK   (44 1904) 433681(Phone) (44 1904) 433681(Fax) Second Author: Michel Demers Carleton University fmdemers@sympatico.ca   Department of Economics, Colonial By Drive Ottawa, K1S 5B6, Canada   (1 613) 420-3744(Phone) (1 613) 520-3906(Fax)