member_states_csts: Cross-sectional time-series data on member states
In jfjelstul/eums: The European Union Member State (EUMS) Database

This dataset is a template for cross-sectional time-series data on member states. There is one observation per member state per year.

1	member_states_csts

A data frame with 6 variables:

key_id: numeric. An ID number that uniquely identifies each observation.
year: numeric. The year.
member_state_id: numeric. An ID number that uniquely identifies each member state.
member_state: string. The name of the member sate.
member_state_code: string. A two-letter code assigned to each member state by the Commission.
years_as_member: numeric. The number of years that the member state has been a member, with the first year of membership coded 1.