We introduce a novel open-access dataset containing information on mean and median age as well as the share of MPs in specific age brackets in party parliamentary groups in lower houses or single chambers of national parliaments. The dataset covers 163 cases from 30 countries and features variables that present these aforementioned shares in relation to the respective group’s presence in the voting-age population (Age Representation Index). Furthermore, the dataset includes the share of women within the party parliamentary groups as well as identifiers that enable matching the dataset with indicators from the Political Party Database (PPDB), the V-Party dataset, PartyFacts and the Manifesto Project Database.

The dataset is accessible via Harvard Dataverse.

And there is an accompanying research note.