Abstract for: The Bass Diffusion Model does not explain diffusion

The Bass Diffusion Model (BDM) is one of the most successful models in marketing research in particular and management science in general. Since publication in 1969, it has guided marketing research on diffusion. This paper illustrates the limitations of the BDM, using mobile diffusion as a context. We fit the BDM to two large developed markets, the USA and Germany, and the emerging markets of Brazil, Russia, India and China. We show that the parameters of the classical BDM may change substantially if the time period considered is changed by a single year. The diffusion of mobile communication does not follow an S-curve in some cases. We do not formulate an empirical alternative, but we suggest the structure of an integrated diffusion mode that treats adoption as one of five phase changes of the diffusion process. We trace the diffusion of mobile communications in India, and show that the integrated diffusion model provides a framework for understanding this case. We show that diffusion is a complex phenomenon, and that simplistic approaches are not equal to the task of explaining it.