Averages are not value-neutral: How ethical theories inform well-being aggregation

As governments and institutions embrace well-being as a policy outcome, aggregating well-being in a population has become commonplace. The default method used to aggregate population well-being is taking the arithmetic mean (average). However, the default of using average well-being as a key performance indicator, while useful, can omit morally relevant information, like the extent of suffering and inequality. Based on a 0-10 point scale of life satisfaction, we examine three alternative methods of well-being aggregation grounded in the ethical theories of: prioritarianism (a weighted average that weighs lower scores heavier), sufficientarianism (the proportion of respondents answering below a ‘suffering’ threshold), and egalitarianism (the degree of inequality) and compare them to the average. Using the Gallup World Poll’s nationally representative data from over 1 million participants in 144 countries from 2019 to 2022, we found that the distribution of life satisfaction deviated significantly from a normal distribution in all countries, suggesting that using the mean and standard deviation cannot adequately capture the full distribution. After reranking countries according to alternative aggregation methods, we find that 17% of the time countries ranked using the Gini coefficient deviate by at least 20 ranks from the default average rankings. Finally, we observed that 27% of the time, increases in average well-being at the country level are accompanied by a rising gap between the top 90th and bottom 10th life satisfaction percentile. Our findings show the limitation in using the average and offer alternatives that are aligned with promoting equitable well-being growth.