Aggregate State Legislator Shor-McCarty Ideology Data, January 2025 update

The Shor-McCarty state legislative aggregate ideology data is being released as an update to the data underlying Shor and McCarty (2011). These are based on individual-level ideal point estimates (called “Shor-McCarty NPAT Scores” or “Shor-McCarty Common Space Scores”) described fully in that article. The updated data is described in Shor and McCarty (2022). We ask you to please cite both papers if you use our data. Estimates are all in NPAT common ideological space to facilitate explicit comparisons across time and between states. The data stretch from 1993 to 2022, newly incorporating the 2020 and 2021 state legislative elections, and filling in a portion of data missing in previous releases. There are now 2,730 aggregate chamber-year observations, compared with 2,519 in the last release.