Estimating Intra-Party Preferences: Comparing Speeches to Votes

Schwarz, Daniel; Traber, Denise; Benoit, Kenneth (2015). Estimating Intra-Party Preferences: Comparing Speeches to Votes. Political Science Research and Methods, 5(02), pp. 379-396. Cambridge University Press 10.1017/psrm.2015.77

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Well-established methods exist for measuring party positions, but reliable means for estimating intra-party preferences remain underdeveloped. While most efforts focus on estimating the ideal points of individual legislators based on inductive scaling of roll call votes, this data suffers from two problems: selection bias due to unrecorded votes and strong party discipline, which tends to make voting a strategic rather than a sincere indication of preferences. By contrast, legislative speeches are relatively unconstrained, as party leaders are less likely to punish MPs for speaking freely as long as they vote with the party line. Yet, the differences between roll call estimations and text scalings remain essentially unexplored, despite the growing application of statistical analysis of textual data to measure policy preferences. Our paper addresses this lacuna by exploiting a rich feature of the Swiss legislature: on most bills, legislators both vote and speak many times. Using this data, we compare text-based scaling of ideal points to vote-based scaling from a crucial piece of energy legislation. Our findings confirm that text scalings reveal larger intra-party differences than roll calls. Using regression models, we further explain the differences between roll call and text scalings by attributing differences to constituency-level preferences for energy policy.

Item Type:

Journal Article (Original Article)


11 Centers of Competence > KPM Center for Public Management

UniBE Contributor:

Schwarz, Daniel


300 Social sciences, sociology & anthropology
300 Social sciences, sociology & anthropology > 320 Political science




Cambridge University Press




Daniel Schwarz Badertscher

Date Deposited:

06 Jan 2016 10:48

Last Modified:

05 Dec 2022 14:50

Publisher DOI:





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