Allanson, R. and Robson, M. (2026). Experimental estimation of preferences on population health ethics Social Choice and Welfare.

We develop a novel social choice experiment capable of estimating preference parameters on population ethics. Our experiment poses three within-subject treatments in which participants allocate scarce resources to determine the health-related quality-of-life, and existence, of two population groups. Within a flexible social welfare function, we estimate participant-level preferences for inequality aversion, average vs total welfare maximisation, and minimum {\textquoteleft}critical level{\textquoteright} thresholds. By combining random behavioural and random utility models we also explicitly model {\textquoteleft}noise{\textquoteright} in decision making. Using a sample of British adults (n = 115, obs. = 5060), we find that 98.7% of respondents are inequality averse, prioritising the worst-off at the expense of efficiently maximising overall health. The modal group of participants (39.2%) maximise total welfare and have a critical level threshold of zero, however there is extensive heterogeneity in participants{\textquoteright} population preferences. We demonstrate how these preferences could be used to aid policymaking, where difficult trade-offs emerge between equity and efficiency, average and total welfare, and population sizes.