Recent advances in computational methods for extracting party positions from political texts have provided scholars promising new ways for estimating party positions. However, existing methods face serious challenges when it comes to producing time-series data. This leaves a gap in the literature on estimating party ideology. We fill this gap by proposing a scaling technique to estimate positions based on word frequencies in political texts. Our technique allows researchers to locate parties in one or multiple elections. We estimate the positions of German political parties from 1990-2005 from word frequencies in party manifestos. The extracted positions reflect changes in the party system more accurately than existing time-series positions. Our method allows us to examine which words are important for placing parties on the left and the right. We find that words with strong political connotations are the best discriminators between parties. Finally, we include a series of robustness checks and demonstrate that our positions are insensitive to distributional assumptions and document selection.
Note: This is an electronic version of an article published in the American Journal of Political Science. Complete citation information for the final version of the paper, as published in the print edition of the American Journal of Political Science, is available on the Blackwell Synergy online delivery service, accessible via the journal's website at www.blackwellpublishing.com/journals/ajps or www.blackwell-synergy.com
Proksch, Sven-Oliver and Jonathan B. Slapin (2009) "Position Taking in European Parliament Speeches", British Journal of Political Science.
This article examines how national parties position themselves in European Parliament (EP) speeches. We apply new computer-based content analysis technique, Wordfish, to estimate party positions in the European Parliament using the word counts in speeches. We test three hypotheses of position-taking in the European Parliament: a left-right ideology hypothesis, a pro/anti-Europe hypothesis, and a national politics hypothesis. Surprisingly, and in contrast to studies of roll call votes, we do not find evidence that national party positions from MEP speeches reflect the parties' overall left-right ideology. Instead, these positions reflect the parties' stance with regard to EU integration and national redistributive characteristics. We test the robustness of our results in a threefold manner. First, we take advantage of the multilingual environment of the European Parliament and show that the estimated positions are robust to the choice of translation (English, French, and German). Second, we use independent measures of national party positions from analyses of roll call votes and two expert surveys. Finally, we apply a range of statistical models to account for measurement error of the independent variables and the hierarchical structure of the data. Our robust findings suggest that the entire corpus of EP speeches reflects partisan divisions over EU integration rather than left-right politics.
Note: This is an electronic version of an article published online in the British Journal of Political Science by Cambridge University Press.
The statistical analysis of political texts has received a prominent place in the study of party politics, coalition formation and legislative decision making in Germany. Yet, we still lack a thorough understanding of the practical conditions under which such analysis produces unbiased estimates of policy positions. We examine the asymptotic behaviour of a recent scaling method called ‘wordfish’. For this purpose, we conduct Monte Carlo simulations to demonstrate the effects of the choice of manifesto texts on party position estimates, including the number of documents included in the analysis and their length. Moreover, we present guidelines on how to process linguistic information for researchers interested in using the technique, focusing specifically on German texts.
Qualitative accounts of Japanese party politics allude to the standard left–right spectrum, but they invariably devote much more space to discussions of foreign policy differences than to socioeconomic conflict. Quantitative estimates of Japanese party positions treat short party responses to newspaper interviews as if they were true manifestos, and fail both to confirm the claims of the qualitative literature and to demonstrate any consistent basis for party differentiation at all. We address both puzzles by applying a text scaling algorithm to electoral pledges to estimate Japanese party positions on three major policy dimensions. Our analysis largely confirms the findings of the qualitative literature, but also offers new insights about party movement and polarization over time.