Metroeconomica. 2020;00:1–23. wileyonlinelibrary.com/journal/meca | 1 © 2020 John Wiley & Sons Ltd 1 | INTRODUCTION The processes and the reasons for democratization of a country are a topic that captures and has captured the attention of several scholars during the last decades. Democracies are known to be Received: March 2019 | Revised: March 2020 DOI: 10.1111/meca.12287 ORIGINAL ARTICLE Can income inequality promote democratization? Laura Policardo 1 | Edgar J. Sanchez Carrera 2,3 Opinions expressed in this publication are those of the authors and do not necessarily reflect the official opinion of the Italian Agenzia delle Dogane e dei Monopoli. 1 Agenzia delle Dogane e dei Monopoli, Sesto Fiorentino, Italy 2 Department of Economics, Society and Politics, University of Urbino Carlo Bo, Urbino, Italy 3 Research Center in Applied Mathematics, Universidad Autónoma de Coahuila, Saltillo, Mexico Correspondence Edgar J. Sanchez Carrera Department of Economics, Society and Politics at the University of Urbino Carlo Bo, Urbino, Italy. Email: edgar.sanchezcarrera@uniurb.it Abstract The aim of this paper is to study the effect of income in- equality on the probability of democratization, in a panel of 51 transition countries during the period 1960–2008. Using a conditional fixed-effect logit estimation, we find robust results suggesting that income inequality (measured by the Gini index of household’s income inequality) has an inverse—U-shaped relation with the probability of transi- tion from autarchy to democracy. We show that there is a turning point at a level of household’s income inequal- ity equal to a Gini index of 40. When income inequality is below 40, then probability of transition is positively related to inequality, but when inequality is higher, a subsequent increase in inequality decreases the probability of democra- tization. This is consistent with Acemoglu and Robinson’s theory that shows how transitions are likeliest at moderate levels of inequality, while autocracy is likelier at the lowest and highest levels of inequality. KEYWORDS democratization, fixed-effect conditional logit, income inequality JEL CLASSIFICATION C23; D63; O40; O54