Heterogeneity of institutions and model uncertainty in the income inequality nexus

This study revisits the drivers of income inequality with political institutions at the core. We take a multidimensional institutional approach by defining political institutions in terms of governance, political freedom, political fragmentation and political scale. We carry out an extensive empirical analysis of the role of political institutions by decomposing it into distinct elements and providing available proxies for each dimension. Considering the difficulty and the lack of consensus and clarity regarding model selection in the literature, we follow a model averaging methodology to deal with the issue of model uncertainty and model specification that impacts the role of institutions. We combine an analysis of club convergence, a clustering mechanism according to the long term income trajectories of the countries, with Bayesian Model Averaging (BMA) to determine the most important variables that affect inequality out of a large set of potential determinants for each homogeneous country clusters in terms of their development path. Our results show that drivers of income inequality do not act the same irrespective of different economic development patterns and that there is no “one size fits all” policy prescription that links political institutions and income inequality.