Dimension Reduction of Legislative Roll Call Votes

Music City Center 

Roll call votes taken in democratic legislative bodies offer a data-rich resource through which to examine political behavior using a quantitative lens. This work explores the performance of different dimensionality reduction techniques when used to assess the relationships among legislators. In particular, expressions of ideological positioning, partisan polarization, and intraparty clusters are compared, as are the stability and robustness of different approaches. Features affecting the embedding, including missed votes and partisan control of the chamber, are also discussed. Data sets are drawn from the Americas and Europe.

dimension reduction

voting behavior

data visualization 

Section on Statistical Graphics