Abstract:Income redistribution is determined, to some extent, by how fair citizens judge the income distribution in their societies to be. Nonetheless, there seems to be a contradiction between what people declare as a fair income distribution, and the increase in inequalities across countries. An unexplored methodological reason for that is that survey instruments do not perfectly capture individual’s perception of income fairness, biasing results. Therefore, in this paper we use data from a Multitrait-Multimethod experiment conducted in wave 6 of the probability-based CROss-National Online Survey (CRONOS) panel in Great Britain, Estonia and Slovenia. Specifically, we explore the effect of three different scales on how fair people report an income to be, and the subsequent measurement quality of these answers. Overall, we find that survey scales do have an impact on what people report as a fair income, and the quality of these answers. Specifically, we find that the use of branching scales increases participants’ likelihood of considering an income distribution as “Fair”, while using partial-labelling and visual clues to separate (fair/unfair) dimensions increases the likelihood of considering these as “extremely unfair high/low.” In addition, our results suggest that using a 9-point fully labelled unfolding scale without visual clues yields the best measurement quality across all countries, being preferred over the other tested methods (9-point partially labelled unfolding scale with visual clues; 9-point fully labelled branching scale without visual clues).