The study of economic growth and social inequality goes back to the works of S. Kuznets, A. Atkinson, P. Krugman, J. Stiglitz, T. Piketti, and B. Milanovic. Statistical analysis of social inequalities for a large set of countries, divided into seven clusters, was conducted for the period 2000–2016. The share of incomes of the 10th decile was used as a measure of inequality. The hypothesis of the positive impact of economic growth on the reduction of social inequality was tested. Stylized facts on an array of 106 countries for the period under review indicate a high degree of stability of the level of inequality in most groups, especially in the most developed countries, and in particular in the Anglo-Saxon ones. The distribution of key socioeconomic and even political indicators for... clusters shows their strong relationship with the structure of cluster inequality. This makes it possible to significantly deepen the analysis, in particular the one concerning the stages of world development.