De Fleur (1956) provides the earliest evidence of diminishing returns. He finds a common logarithmic pattern for leaflets dropped and message recalled in field experiment. Since then, many researchers have applied logarithmic or square root patterns to capture the effect of diminishing returns...

The concept of Integrated Marketing Communications (IMC) emphasizes the role of synergy, which arises when the combined effect of multiple activities exceeds the sum of their individual effects. In this paper, we investigate the effects of synergy on the profitability of IMC programs in...

In Markov-switching regression models, we use Kullback-Leibler (KL) divergence between the true and candidate models to select the number of states and variables simultaneously. In applying Akaike information criterion (AIC), which is an estimate of KL divergence, we find that AIC retains too...