The index of local autonomy, developed by European experts, is a relatively new tool for quantitative measurement of the state of local self-government as a social phenomenon. The introduction of a quantitative approach into qualitative analysis and a reasonable combination of both methods allow avoiding the negative consequences of the dominance of each method in social research, including the analysis of the evolution of local self-government. The index is an attempt to objectify the level and dynamics of the development of local autonomy as the most important characteristic of this institution. The calculation of the index is based on 11 indicators that take into account the legal, political and organizational aspects of the autonomy of local self-government. For the first time, the LAI index was calculated in 2014, and in 2021 LAI 2.0 was calculated for the first time for Russia (including by the author of the article). The article presents the meaning and methodology for calculating the index, which can be taken into account for the current reform of public authority. It should be aimed at improving the efficiency of local self-government, which is facilitated by the level of its autonomy.