Advertising Expenditure, Enplanement, and Market Concentration

This paper investigates the long-run relationship between advertising expenditure and enplanement (representing the number of passengers boarding an aircraft), advertising expenditure across carriers, and advertising expenditure and market concentration for the six largest US airlines. Advertising expenditure is evidenced to be strategic, although not clearly effective at increasing enplanement, suggesting collusive behavior. Advertising is also evidenced to be, for the most part, balancing in nature across rival carriers. Further tests suggest a positive and linear relationship with positive bi-directional causality between advertising and market concentration. This paper's findings raise three important questions. First, if advertising is not clearly effective at increasing enplanement, then why advertise? Second, if advertising increases market concentration, then shouldn't airline activities be under some degree of scrutiny, or even be partially regulated? Third, could airline advertising be important in explaining higher post-deregulation fares?