Leshanych M. Peculiarities of the process of institutionalization of political parties and the party system of Ukraine in the conditions of democratic transit.

The thesis analyzes the peculiarities of the process of institutionalization of political parties and the party system of Ukraine in the conditions of democratic transit. Methodological tools have been developed to research the process of institutionalization of political parties and the party system of Ukraine. The index of institutionalization of political parties has been developed, and on its basis the level of institutionalization of Ukrainian political parties has been measured. The following periodization of the process of legal institutionalization of Ukrainian political parties is proposed: Stage 1: 1991–1996; Stage 2: 1996–2001 / 2002; Stage 3: 2002-2015; Stage 4: from 2015 to the present. Based on the analysis of the process of institutionalization of the Ukrainian party system during 1991–2019, the main factors have been identified that determined it at different stages of its development. It has been stated that the development of the party system since 2014 has been characterized by a high level of volatility and non-partisanship of people’s deputies, low vote for “old” parties and a radical change in the actor structure of the party system, which indicates a low degree of its institutionalization.