Margaret E. Slade
A dynamic model of product rivalry is developed for a market in which firms choose price and advertising intensity. The model, a state-space game, is implemented using data that consist of weekly price, sales, and promotional activity for four brands of saltine crackers sold by four chains of grocery stores in a small town. A number of questions can be asked of this data. First, is advertising predatory (merely changing market shares) or cooperative (shifting out market demand)? Second, are price and advertising own and cross-strategic complements or substitutes? And finally, do investments in stocks of goodwill and in price reductions make firms tough and aggressive or soft and accommodating?