Bass model revisited

 

P. C. Jha

 

Anshu Gupta y

 

P. K. Kapur z

 

Department of Operational Research

University of Delhi

Delhi 110 007

India

 

Abstract

 

Innovation Diffusion model due to Bass has been widely used in the literature and has found applications in several areas. The model categorizes the consumers into two categories viz. innovators and imitators. The model is based on simple assumptions and excludes some real life consumer behavior and market aspects. Further extension of the model results in complex mathematical form or is sometimes not possible to solve. This difficulty can be resolved using an alternative formulation of the model maintaining its flexible structure. In this paper we propose some extensions of the Bass model using the alternative formulation. Promotional effort is an important component of marketing mix that determines the success of a product in the market and should be incorporated in the diffusion model. The Generalized Bass model (GBM) developed by Bass can be used to predict the growth of sales incorporating current marketing effect. Like Bass model GBM is also based on simple assumptions and excludes some real life consumer behavior and market aspects. Further extension of GBM also results in complex mathematical form or is sometimes not possible to solve. In this paper we have derived an alternative solution of the Generalized Bass model maintaining its flexible structure. We have called current marketing effect as a measure of promotional efforts. The utility of this alternative derivation has been highlighted through new models that describe growing market size and repeat purchasing. The models have been validated on new product sales data sets cited in literature.

 

Keywords: Innovation diffusion, new product, growing market size, repeat purchasing, promotional efforts.