Bayesian Changepoint Model for Text Data

Exploring and identifying structural changes in the characteristics of or relationships between political actors is one of the fundamental goals of political science. Some changes can be identified using documents (latent traits) include positions of parties/legislators from manifestos/press releases, and relationships between countries from treaties. The proposed model simultaneously estimates topics (contents of the documents), the location of changepoints, and the number of changepoints (no need to compare multiple models). It considers multiple latent traits in documents (a topic-model based approach), shows which topics (characteristics) contribute to change, and identifies multi-level changes (hierarchical changepoint).