Can We Assume Research Participants are Utility Maximisers?

Abstract

Rational: Preference elicitation techniques are extensively used in economic evaluations to evaluate, guide service provision and budget allocation of finite resources. These preference elicitation techniques are based upon the implicit assumption of utility theory and its primary axiom of utility maximisation. Objectives: Experimentally test by means of an information manipulation if utility maximisation is being used in relation to the hypothetical decision of participating in cancer genetic testing and counselling. Methods: A repeated measures information manipulation experiment was conducted with a sample of 158 (142 after exclusions) first year undergraduate students. Participants were randomised into positive, negative and control groups. The positive group were given information on detection and prevention of genetic breast cancer, the two negative groups received the same information in addition to information on the limitations of these methods (2 groups were used to prevent a primacy effect), and the control group were given information relating to the common cold. Results: Statistical analysis using repeated measures GLM and examination of descriptive statistics revealed that the information manipulation did not induce the hypothesised changes in, the perceived benefits and barriers respondents associated with genetic testing and counselling for breast cancer, or respondents likelihood of opting to have testing and counselling. Correlation revealed a small to moderate relationship between the ratio of benefits and barriers associated with testing and counselling and the likelihood of opting to have testing and counselling at baseline (r=0.191, p<0.05) and follow-up (r=0.404, p<0.001). Discussion & Conclusions: There was no evidence of utility maximisation, the key tenet of utility theory, being used. The results of the current experiment cast further doubt upon the merits of utility theory as a descriptive model. There is a need to conduct further research into utility theory in its various forms as soon as possible, as until the uncertainty relating to its descriptive validity are resolved, all analytical techniques based upon it are potentially invalid.