How do respondents explain WTP responses? A review of the qualitative evidence

Alongside a growing body of empirical research relating to willingness to pay (WTP) valuations of the environment, health and safety, there is mounting evidence of embedding, framing effects and other anomalies in responses. Gaining an understanding into how respondents arrive at WTP values is crucial to determining the possible reasons for such anomalies and helping to construct more ‘valid’ WTP instruments.This paper reports a comprehensive literature review of qualitative research conducted alongside the elicitation of WTP values in the areas of environment, transport safety and health. Our review revealed a paucity of work in this area and the need for further in-depth studies of this kind. Despite a wide range of studies in different sectors, with different focus in terms of the nature of the goods in question and the objectives of the qualitative studies, we identify four preliminary themes: mental accounting, lack of trust, moral outrage and moral satisfaction. The relevance of such findings for the design and interpretation of WTP studies is discussed.