Comment on A.S.C. Ehrenberg's paper
On the first place, it has to be said that the group members consider it as a jolly good idea to observe the purchasing habits over quite long periods of time instead of making conclusions based on elementary purchasing behaviour. But they regret that the authors have not (or not yet) studied the relationship between the duplications and the D coefficients observed for specified pairs of brands during successive periods. It could be an interesting direction for research to analyse these data on the way it has been done with elementary purchases when applying Markovian processes.
- This could also be of interest