Skip to main content

Measuring Political Positions from Legislative Speech

  • Benjamin E. Lauderdale (a1) and Alexander Herzog (a2)

Existing approaches to measuring political disagreement from text data perform poorly except when applied to narrowly selected texts discussing the same issues and written in the same style. We demonstrate the first viable approach for estimating legislator-specific scores from the entire speech corpus of a legislature, while also producing extensive information about the evolution of speech polarization and politically loaded language. In the Irish Dáil, we show that the dominant dimension of speech variation is government–opposition, with ministers more extreme on this dimension than backbenchers, and a second dimension distinguishing between the establishment and anti-establishment opposition parties. In the U. S. Senate, we estimate a dimension that has moderate within-party correlations with scales based on roll-call votes and campaign donation patterns; however, we observe greater overlap across parties in speech positions than roll-call positions and partisan polarization in speeches varies more clearly in response to major political events.

Corresponding author
e-mail: (corresponding author)
Hide All

Authors’ note: Replication materials are available online as Lauderdale and Herzog (2016). We thank Ken Benoit, Royce Carroll, Justin Grimmer, Paul Kellstedt, Lanny Martin, Scott Moser, Adam Ramey, Randy Stevenson, Georg Vanberg, two anonymous reviewers, and the editor of this journal for their comments and feedback. Supplementary materials for this article are available on the Political Analysis Web site.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Political Analysis
  • ISSN: 1047-1987
  • EISSN: 1476-4989
  • URL: /core/journals/political-analysis
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
Type Description Title
Supplementary materials

Lauderdale and Herzog supplementary material

 PDF (366 KB)
366 KB


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 176 *
Loading metrics...

Abstract views

Total abstract views: 566 *
Loading metrics...

* Views captured on Cambridge Core between 4th January 2017 - 19th March 2018. This data will be updated every 24 hours.