Absftact. Following the publication of the Bass model in 1969 in Management Scienceth, e earliestattempt to modify this model to include decision variableswasan often-cited 1975 paper by Robinson and Lakhani thar was also published inManagemenSt cierceI.n the ensuingyearsnumerous modifications and extensionsofthe Bassmodel havebeenproposedto study the effectsof decisionvariableson thediffusion processfor new products.’wereview here the variouspublishedpapersthatinclude decisionvariablesin diffusion models.In evaluatingthesepublicarionsweprovidebenchmarksof desirablepropertiesof diffirsionmodelswith markering-mixvariables.In further discussionand exploration of desirableproperries for suchmodels we presentand evaluateproportional-hazardmodels,originally proposedbyCox (1972) for application to surrrival data, that include decision variables.Weprovide a comparison of these models with the generalizedBassmodel developedby Bass,Krishnan, andJain (1994).Wb conclude with a discussionof the limitationsof the generalizedBassmodel and suggestpossibleareasfor future research