Has brand loyalty declined? A longitudinal analysis of repeat purchase behavior in the UK and the USA

This research examines long-term loyalty change in a wide variety of FMCG categories in the UK and the USA, over time periods ranging from six to thirteen years. The study uses three loyalty measures: polarization index (φ), average brand share of requirements (SCR), and average repertoire size. Analysis over 26 categories shows mixed results for the proposition that brand loyalty is declining. Overall, there is a very small decline in average SCR of 0.9 percentage points per year; but no statistically significant change in polarization and repertoire size over time. Indeed while some specific categories exhibit slight loyalty declines others show small increases. Furthermore, several of the loyalty measures are negatively correlated with category purchase frequency and the number of SKUs in the category — that is, if these category factors increase in a year, loyalty declines somewhat in the year.