A Comparison of Market Share Models and Estimation Procedures

The authors compare market share models differing in terms of functional form, estimation procedure, and level of parameterization. They evaluate the models by testing the accuracy of predicted shares as well as the validity of the estimated parameters. The tests indicate that valid parameter estimates and similar forecasts are obtained with linear, multiplicative, and attraction models. Better share forecasts generally are obtained from models with brand-specific parameterization and OLS estimation. Most of these conclusions are contrary to previous findings. Several implications for researchers are discussed.