The Polity project is one of the most widely used data resources for studying regime change and the effects of regime authority. Polity5 Project, Political Regime Characteristics and Transitions, 1800-2018, annual, cross-national, time-series and polity-case formats coding democratic and autocratic ''patterns of authority'' and regime changes in all independent countries with a total population greater than 500,000 in 2018 (167 countries in 2018).