Intermedia substitutability and market demand by national advertisers

We assess substitute and complementary relationships among eight national advertising media classes, as well as the magnitude of their own-price elasticities. We employ a translog demand model, whose parameters we estimate by three-stage least squares, based on 1960-94 annual U.S. data. We find aggregate demand by national advertisers for each of the eight media is own-price inelastic, and that cross-price elasticities suggest slightly more substitute than complementary relationships, although both are rather weak. These patterns are consistent with long prevailing institutional arrangements and media selection practices.