Forecasting computer sales and generation of end-of-life computers in the U.S.

Our goal is to characterize future trends in the generation of obsolete computers in the U.S. Our definition of obsolete is based on a user purchasing a replacement computer, after which the old one is stored, resold, or sent for waste management. Starting from historical sales data on new computers and assuming a plausible first life span distribution of desktop and laptop computers, the historical penetration rate is expressed in terms of the number of computers owned per capita. We then work to extrapolate the current trend to the future by using a logistic model [L.D. Frank, 2004], an S-shaped curve based on a rate constant and a carrying capacity, the latter expressing the asymptotic limit of adoption of the technology.