The behavioural consequences of political solidarities: Validating the solidarity game on a representative online sample with real-time interaction in oTree

Political solidarities are considered a normative cornerstone of modern civil societies and a key source of resilience towards anti-democratic threats. Despite its fundamental importance, little is known about the behavioural consequences of existing attitudinal solidarity measures. This study asks, how can we best measure political solidarities, i.e., the individual willingness to support public transfers in favour of others? Political psychology and sociology frequently aim to measure the multi-dimensional concept of political solidarity using survey items (e.g. WVS). However, experimental political science points to methodological shortcomings of attitudinal measures and highlights the benefits of incentivized behavioural measures to elicit social preferences. Following this critique, we implement the solidarity game by Selten & Ockenfeld (1998) using oTree and replicate their study design on a representative online access sample with real-time interaction. In the post-experimental survey, we collect a full range of attitudinal solidarity measures to explore the behavioural consequences of attitudinal measures on subjects’ behaviour in the solidarity game. The study enables us to identify robust measures of political solidarities that open new avenues for exploring the relationship between political solidarities, identities, and ideologies.