Fair and Balanced - measuring media bias

One hears charges from both left and right about media bias, with FOX News frequently cited as the most extreme case. Tim Groeling has done interesting work to objectively measure the bias shown by television media, in a paper (PDF here) to be published in the December issue of Presidential Studies Quarterly. He simply collected the in-house presidential approval polling by ABC, CBS, NBC and FOX News and compared these with the actual broadcasts of such polls on evening news shows from 1997 to early 2008. As an example, CBS was 35 percent less likely to report a five-point drop in approval for Bill Clinton than a similar rise in approval and was 33 percent more likely to report a five-point drop than a rise for George W. Bush. FOX News was 67 percent less likely to report a rise in approval for Clinton than a decrease and 36 percent more likely to report an increase rather than a decrease for Bush.