The authors analyze primary demand effects of marketing efforts directed at the physician (detailing and professional journal advertising) versus marketing efforts directed at the patient (direct-to-consumer advertising). The analysis covers 86 categories, or approximately 85% of the U.S. pharmaceutical market, during the 2001㤼㸶2005 period. Primary demand effects are rather small, in contrast with the estimated sales effects for individual brands. By using a new brand-level method to estimate primary demand effects with aggregate data, the authors show that the small effects are due to intense competitive interactions during the observation period but not necessarily to low primary demand responsiveness. In contrast with previous studies, the authors also find that detailing is more effective in driving primary demand than direct-to-consumer advertising. A category sales model cannot provide such insights. In addition, a category sales model likely produces biased predictions about period-by-period changes in primary demand. The suggested brand-level method does not suffer from these limitations.
Keywords: primary demand effects, marketing-mix effects, econometric models, pharmaceutical marketing