Earlier versions of this work were presented at the 2003 annual meeting of the Midwestern Political Science Association, 2003 annual meeting of the Society for Political Methodology, and the 2003 annual meeting of the American Political Science Association. We thank Larry Bartels, Neal Beck, Jon Bendor, Bruce Bueno De Mesquita, Alberto Diaz, Jim Fearon, William Jacoby, Steve Krasner, David Laitin, Jeffrey Lewis, Nikolay Marinov, Andrew Martin, Doug Rivers, and Mike Tomz for useful comments and references. Errors and omissions remain our own responsibility.
Democracy as a Latent Variable
Article first published online: 18 JAN 2008
American Journal of Political Science
Volume 52, Issue 1, pages 201–217, January 2008
How to Cite
Treier, S. and Jackman, S. (2008), Democracy as a Latent Variable. American Journal of Political Science, 52: 201–217. doi: 10.1111/j.1540-5907.2007.00308.x
- Issue published online: 18 JAN 2008
- Article first published online: 18 JAN 2008
We apply formal, statistical measurement models to the Polity indicators, used widely in studies of international relations to measure democracy. In so doing, we make explicit the hitherto implicit assumptions underlying scales built using the Polity indicators. Modeling democracy as a latent variable allows us to assess the “noise” (measurement error) in the resulting measure. We show that this measurement error is considerable and has substantive consequences when using a measure of democracy as an independent variable in cross-national statistical analyses. Our analysis suggests that skepticism as to the precision of the Polity democracy scale is well founded and that many researchers have been overly sanguine about the properties of the Polity democracy scale in applied statistical work.