Competitive Advertising Strategies and Market-Size Dynamics: A Research Note on Theory and Evidence
分析动态市场规模下企业的竞争性广告策略，结合Bass扩散模型和Lanchester模型，推导最优广告策略的理论解，并用宝丽来和柯达的即时摄影数据估计参数，计算最优广告支出轨迹。
This paper analyzes competing firms’ advertising strategies in markets characterized by dynamic market sizes. For new product innovations, a large literature has been developed on the basis of the celebrated Bass diffusion process, which captures what we call market-size dynamics. However, in spite of the significant literature incorporating competitiveness into the Bass model, few if any analytical results have been obtained, especially those with normative implications. On the other hand, important theoretical and empirical insights have recently been obtained using the famous Lanchester warfare model of competition, in which market-share dynamics are governed by advertising activities for mature products whose market sizes are typically fixed or stable. Our paper seeks to address the issue of optimal advertising strategies incorporating both market-share dynamics and market-size dynamics. In doing so, we seek to take advantage of the theoretical and normative insights currently available in the Lanchester formulation for mature products to obtain normative, analytical results on competitive advertising strategies for new product innovations whose markets evolve around the Bass process. We first obtain analytical solutions to the problem at hand and offer theoretical implications for competitive advertising on the Bass diffusion model. The model’s parameters are then estimated using a set of data on sales and advertising expenditures of Polaroid Corp. and Eastman Kodak Co. in instant photography during the 1976–1985 period; optimal trajectories for the firms’ advertising spending are then calculated, and other marketing and managerial implications of optimal advertising strategies are explored.