Measuring hearts and minds: A validated survey module on inequality aversion and altruism[Mesurer les cœurs et les esprits : un module d'enquête validé sur l'aversion pour les inégalités et l'altruisme]

Social preferences are widely studied in behavioral economics, with some validated survey modules to measure trust, altruism and reciprocity. Despite growing interest in inequality aversion-defined as an individual's dislike of disparities in outcomes-there is, however, no dedicated and validated module to assess this specific social preference. Moreover, inequality aversion and altruism are often hard to disentangle, which points to the need for a unified module that incorporates both preferences. To bridge these gaps, we introduce a novel survey module that captures general attitudes toward inequality aversion and altruism. This module was developed and validated through an experimental study with a representative U.S. population sample. Our results demonstrate that the proposed module effectively captures variations in both inequality aversion and altruism, with consistent reliability across individual heterogeneity. This tool offers researchers a standardized and generalizable approach for measuring inequality aversion and altruism, paving the way for future studies and across diverse contexts.