Diffusion and Advertising: The German Telephone Campaign

The goal of the present paper is to investigate the influence of advertising on the diffusion of new telephones in West Germany. Several alternative ways of integrating advertising into the well-known Bass-diffusion-model are suggested and empirically tested. The econometric investigation yields results which are consistent with the behavioral assumption. A model which assumes that advertising mainly influenced the demand of imitators is accepted as the most valid representation of reality. The lag structure of advertising response was best captured by a Nerlove-Arrow-model. Advertising attained its maximum effect after several months. A cumulative measure of the total advertising effect is suggested and quantified. Directions for potential generalizations are discussed.