The Product Life Cycle in the Commercial Mainframe Computer Market, 1968- 1982

We investigate product life cycles in the commercial mainframe computer market. We use hazard models with time-varying covariates to estimate the probability of product exit and Poisson models to estimate the probability of introduction. We measure the importance of different aspects of market structure, such as the degree of competitiveness, cannibalization, vintage, product niche, and firm effects. We find evidence of a relationship between the determinants of product exit and product entry.