Re-measuring left–right: A comparison of SEM and Bayesian measurement models for extracting left–right party placements

Abstract

This paper demonstrates the relative strengths and weaknesses of SEM and Bayesian approaches to combining different sources of data when estimating latent variables. Data on party left–right positioning collected from party manifestos and surveys of party experts, MPs and voters are used to illustrate the two techniques. Although widely used and accepted, the SEM approach is less useful than the Bayesian approach, particularly when using the latent variable in subsequent predictive estimations.