| The boundaries that devine competition are subject to environmental changes, such as technological advances or evolving consurmen preferences [Day, Shcoker and Srivastava 1979]. As compettive boundaries fluctuate, competitors can emerge from new or unanticipated produc categories. Recently, Shcoker bayus end kim [2004] urged additional research on the scope and cricumstances under which intercategory competition takes place [i.e., competition among products from different products categories]. this article responds to that call by intergrating four froms of competition described in the marketing, management, economics, and psychology literatures. |