Decomposing the effect of advertising: What happens in the retail channel?

Abstract

The diverging interests of manufacturers and retailers famously give rise to the double marginalization problem but have consequences far beyond pricing. Advertising is another marketing instrument that is under the control of the manufacturer but its ultimate effect on consumer demand also depends on retailers’ pricing decisions. We decompose the effect of advertising in the channel and highlight an additional route through which advertising affects sales, namely via the changes in the retail price that a strategic retailer makes in response to changes in demand following manufacturer advertising. The total demand effect of advertising thus comprises the direct effects of advertising on market shares, and the indirect effects coming through adjustments that the retailer makes to the in-store prices of all the brands in a given product category in response to the shifted demand due to advertising. We match advertising data for four different categories (both food and non-food) to store-level scanner panel data, which also include information on wholesale prices. Controlling for wholesale prices, we establish in a reduced-form model that the retailer reacts to manufacturer advertising by changing retail prices instead of simply imposing a constant markup on the wholesale price. To further explore the role of the strategic response of the retailer in a systematic fashion and quantify the effects derived in the decomposition, we estimate a discrete-choice model of demand and determine the magnitude of the direct and indirect effects. We find that the indirect effect of advertising through retailer prices is about half the size of the direct effect, and thus substantively affects advertising effectiveness.