Movie Review Bias: Time Warner vs. News Corp.

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Does media concentration lead to biased coverage? A new paper from two Berkeley economists, Stefano Delavigna and Alec Kennedy, studies News Corp. and Time Warner, and approaches the big question through a small window: movie reviews. Here’s the abstract:

Fueled by the need to cut costs in a competitive industry, media companies have become increasingly concentrated. But is this consolidation without costs for the quality of information? Concentrated media companies generate a conflict of interest: a media outlet can bias its coverage to benefit companies in the same group. We test empirically for bias by examining movie reviews by media outlets owned by News Corp.–such as the Wall Street Journal–and by Time Warner–such as Time. We find a statistically significant, if small, bias in the review score for 20th Century Fox movies in the News Corp. outlets. We detect no bias for Warner Bros. movies in the reviews of the Time Warner outlets, but find instead some evidence of bias by omission: the media in this group are more likely to review highly-rated movies by affiliated studios. Using the wealth of detail in the data, we present evidence regarding bias by individual reviewer, and also biases in the editorial assignment of review tasks. We conclude that reputation limits the extent of bias due to conflict of interest, but that nonetheless powerful biasing forces are at work due to consolidation in the media industry.

The study takes into account a half million reviews from 1985 (when Newscorp. acquired 20th Century Fox) to 2011. The researchers found that News Corp. reviews of 20th Century Fox movies were slightly more positive than average, “by 2.3 points out of 100, the equivalent of one extra star every 11 reviews.”  Time Warner, on the other hand, had a bias of omission – movies that were likely to be badly reviewed simply weren’t reviewed at all.
A bias of omission brings to mind Rupert Murdoch‘s phone hacking scandal, and the way some of News Corp.’s subsidiaries have covered it. While The Guardian and CNN gleefully reported about red hair and badly aimed pies, Fox News and the Wall Street Journal have touched the story sparingly and with great delicacy.