A substitution and diffusion model with exogenous impact: forecasting of IMT-2000 subscribers in Korea

The demand forecasting for new telecommunication services has used on modeling the diffusion process, because many new services are based on technological innovations. The original work of modeling diffusion process by Bass (1969) is a model of timing for adoption. The Norton and Bass (1986) multi-generation model is the extension of the classical Bass model to the multi-generation situation. The mobile communication service market of Korea has an outside impact by the service providers that makes the direct use of the Norton and Bass model impossible. In this paper, we discuss the problems of existing forecasting models and propose a new model for the forecasting of IMT-2000 subscribers in Korea. The forecast of IMT-2000 subscribers is provided.