A working paper at the National Bureau of Economic Research indicates that the notion of media bias is quite possibly real.
Does media bias affect voting? Over 70 percent of Americans believe that there is either a great deal or a fair amount of media bias in news coverage. Evidence of bias ranges from the topic choices of the New York Times to the choice of think tanks to which the media refer in their broadcasts.
In The Fox News Effect: Media Bias and Voting (NBER Working Paper No. 12169), authors Stefano DellaVigna and Ethan Kaplan address this question by looking at the entry of Fox News into cable markets and its subsequent impact on voting. Between October 1996 and November 2000, the conservative Fox News Channel was introduced into the cable programming of 20 percent of American towns. Using voting data for 9,256 towns, the authors investigate whether Republicans gained vote share in towns where Fox News entered the cable market by the year 2000.
They find that the introduction of Fox News had a small but statistically significant effect on the vote share in Presidential elections between 1996 and 2000. Republicans gained an estimate of between 0.4 and 0.7 percentage points in the towns that broadcast Fox News. They also find that Fox News had a significant effect on Senate vote share and on voter turnout. Their estimates imply that Fox News convinced 3 to 8 percent of its viewers to vote Republican according to a first audience measure, and 11 to 28 percent according to a second, more restrictive audience measure.
Most people, I think, would agree that the Fox News Channel is more to the right than the other news programs on televisions. Further, the fact that the introduction of the Fox News Channel does have a measurable effect on voting behavior argues that there is indeed a media bias. While it is questionable that media bias might influence voting behavior, the converse observation, that the introduction of a news program influences voting behavior points strongly to media bias. This is the second study that I have seen that points to media bias.
The first is this article, published in the Quarterly Journal of Economics (obviously), also points to media bias. Interestingly enough, the Drudge Report comes out as the news entity that is most in line with the political leanings of the general public (according to the measures in the article). This picture shows the distribution of various politicians, news shows, and so forth.
Another interesting part of the research is that if this is true, that media bias also influences voting patterns, then it raises some issues for deregulation of the media markets.








