Scale and scope effects on advertising agency costs

Economies of scale are evident when a firm’s average costs decline while its output expands, as when an advertising agency raises its gross income by serving more accounts and/or larger accounts. Economies of scope appear when cost savings can be realized by a single agency producing several products jointly, as compared to many agencies each producing them separately. How important are economies of scale and scope in advertising agency operations? In this paper cost models are formulated which represent how the principal component of agency costs, employment level, varies according to the mix of media and services an agency provides and the total volume of advertising it produces. These models are estimated and tested cross-sectionally utilizing data pertaining to the domestic operations of 401 U.S. agencies for 1987.