Estimating the effect on happiness through question randomization: An application to blood donation

We rely on the randomized activation of the heuristic of attribute substitution to analyze the effect of blood donation on donors' happiness. We randomly delivered two versions of a questionnaire where the happiness question is alternatively placed immediately before or after a categorical question asking about the blood donor condition of the respondent (non-donor, previously donor, donor). By comparing the answers given to the happiness question in the two versions, we find a positive effect of donating blood on donors' happiness. We discuss the pros and cons of this method to investigate the determinants of subjective well-being.