The role of cost and response-efficacy in persuasiveness of health recommendations.

The persuasiveness of a health recommendation, among other things, is a function of the cost of engaging in the recommended behavior--such as money, time, effort, and discomfort--and the response-efficacy, defined as the likelihood that adherence to the recommendation would lead to the desired goal. This research investigates how cost and response-efficacy combine when influencing persuasion. Several theories of health behavior view cost and response-efficacy as having independent effects on persuasion, that is, a weighted additive impact. This research posits, and finds empirical support for the idea that cost and efficacy combine in a multiplicative fashion to influence persuasion, and suggests a structural modification to the traditional models of the relationship between cost, response-efficacy, and persuasion.