Brand inequalities in the loyalty-effects of purchases

Abstract

Choice models in marketing have generally included the effects of loyalty on individual choice behavior.Loyalty has been typically measured as proportion of purchases or as an exponentially smoothed index of past purchases. An underlying assumption of both measures is that all brands gain the same increase in loyalty with a purchase. However, such an assumption may not hold when the competing brands are not comparable. We propose a new exponential smoothing measure which incorporates brand-specific parameters for the loyalty effects of purchases. A choice model, calibrated on individual level data for the detergent category, is used to compare the proposed measure with its traditional version. This comparison reveals that the new approach improves both the fit and predictive performance of the choice model. The results also suggest that the loyalty effects of purchases are likely to be lower for brands which are purchased on price promotions and higher for expensive brands.