PREDICTING ADVERTISING EXPENDITURES USING INTENTION SURVEYS

In this article we study the use of intention surveys to predict the e ffects of a possible entrant. The case under investigation deals with the introduction of private broadcasting in the Netherlands. Several p redictions of the advertising expenditures in various media are given which depend on a number of scenarios. These scenarios are used to red uce the discrepancies between behavioural intentions and actual behavi our. The predictions of the most realistic scenario are compared with their realizations, and the differences are analyzed. To this end the prediction error is decomposed into an intention error and a sampling error. This decomposition offers good opportunities to analyze discrep ancies between intentions and actual behaviour.