On the numerical forms of contingent valuation responses

Responses elicited by means of contingent valuation are often expressed in numerical forms termed “prominent numbers”, characterised by inexactness. This might arise because subjects find exactness in response unnecessary or valuation tasks intrinsically difficult. It has been suggested that the provision of numerical cues could influence the ease of completion of the valuation task, and thus its outcome. We describe an experiment undertaken to test three hypotheses. These are, first, that the perceived level of difficulty of the valuation task falls as the exactness of numerical cues provided to subjects increases. Second, it is hypothesised that subjects choose values characterised by higher degrees of exactness if they have been cued by numbers characterised by higher degrees of exactness. Third, the size of the chosen value is expected to be lower if the perceived task difficulty is higher. All three hypotheses are supported. Potential explanations for, and implications of, these findings are discussed.