Estimating Spatial Preferences from Votes and Text

We introduce a model that extends the standard vote choice model to encompass text. In our model, votes and speech are generated from a common set of underlying preference parameters. We estimate the parameters with a sparse Gaussian copula factor model that estimates the number of latent dimensions...

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Bibliographic Details
Main Authors: Kim, In Song, Londregan, John, Ratkovic, Marc
Other Authors: Massachusetts Institute of Technology. Department of Political Science
Format: Article
Published: Oxford University Press 2018
Online Access:http://hdl.handle.net/1721.1/118644
https://orcid.org/0000-0002-5774-1585
Description
Summary:We introduce a model that extends the standard vote choice model to encompass text. In our model, votes and speech are generated from a common set of underlying preference parameters. We estimate the parameters with a sparse Gaussian copula factor model that estimates the number of latent dimensions, is robust to outliers, and accounts for zero inflation in the data. To illustrate its workings, we apply our estimator to roll call votes and floor speech from recent sessions of the US Senate. We uncover two stable dimensions: one ideological and the other reflecting to Senators' leadership roles. We then show how the method can leverage common speech in order to impute missing data, recovering reliable preference estimates for rank-and-file Senators given only leadership votes.