Quarterly Journal of Political Science > Vol 6 > Issue 1

Shifting Ideologies? Re-examining Media Bias

  • John T. Gasper 1

[1]John T. Gasper, Visiting Assistant Professor of Political Science, Carnegie Mellon University in Qatar, USA, gasper@andrew.cmu.edu


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Table of contents

The Data and Model
Structural Model

Quarterly Journal of Political Science

(Vol 6, Issue 1, 2011, pp 85-102)

[Research note]

DOI: 10.1561/100.00010006


This research note engages the current research on measuring media bias. I present a reanalysis of the results found in Groseclose and Milyo (2005) and show that the original parameter estimates of the ideological positions of media outlets are not stable over time. Using the same data but analyzed over different periods of time, I find a different conclusion than the previous article. I examine four-year rolling time periods and find that the data produce different parameter estimates in the early- to mid-1990s as compared to after 2000, with all analyzed outlets appearing more moderate or conservative in later time periods. My results indicate that the estimated positions are sensitive observations in the data and the time period of observation of the outlet.

An erratum for this article can be found on the Accompanying Work tab

Data Files

Replication Data | 100.00010006_supp.zip (ZIP),

This file contains the data that is required to replicate the data on your own system.

DOI: 10.1561/100.00010006_supp


Quarterly Journal of Political Science, Volume 6 Issue 1, 10.1561/100.00010006_err