The weak force school vs the strong force school

Andrew Ehrenberg & John Philip Jones

A deep and hitherto unresolved difference of opinion between two schools of advertising: those who believe advertising is a strong force, represented by John Philip Jones, and those who believe advertising is a weak force, led by Andrew Ehrenberg.


On the basis of his analysis of databases of consumer brand-buying behaviour over long periods of time and many product/service categories, Ehrenberg (1998) concluded that (a) brand-buying behaviour is usually very stable and habitual; (b) buying intentions are also stable and predictable; and (c) there is no evidence for the occurrence of persuasive effects. He summed up his conclusions: 'There is no proof that advertising generally acts as a strong force, by persuading people to change radically what they do, believe or feel.'