The UI recipiency rate in each state is the share of unemployed workers who are receiving unemployment insurance benefits through the state’s regular UI program (i.e., not through federal emergency programs such as Pandemic Unemployment Assistance). We use a simple average of UI recipiency rates within the high-, medium-, and low-union-density state groupings. Union density is defined as the share of workers in the state who are represented by a union, including union members and other workers who are covered by a union contract, based on the variable “union” from EPI extracts of CPS-ORG microdata. Low-union-density states are the 17 states with the lowest average union densities from 2022–2024 (with union densities ranging from 3% to 8%). Medium-union-density states are the 17 states (including D.C.) in the middle of the union-density rankings (with union densities ranging from 8.2% to 13.1%). High-union-density states are the 17 states with the highest average union densities from 2022–2024 (greater than 13.4%). See Table 1 for more detail about these groupings. We average union density data across 2022 to 2024 for each state to give a more accurate estimate of states’ typical unionization rates over time.