Study finds correlation between Russian social media trolls and 2016 polling

A new study found a correlation between retweets of known Russian troll accounts during the 2016 election and Donald Trump's poll numbers.

Why it matters: The study, conducted by a team headed at the University of Tennessee-Knoxville and published in the peer-reviewed University of Illinois-Chicago journal "First Monday," suggests that — despite protests to the contrary by Republicans and Trump allies — the Russian disinformation campaign was successful in influencing the 2016 election.

Caveat: Correlation does not always mean causation. If a Trump talking point encouraged a particularly viral Tweet, for example, it may have also encouraged a change in Trump's polling on its own.

• It's also worth noting that the U.S. intelligence community has not conclusively weighed in on whether Russia's interference in 2016 had a tangible impact on the results of the election.

Details: The Tennessee-Knoxville study analyzed 770,005 tweets in English from known Russian troll accounts, as well as corresponding poll data from FiveThirtyEight's archive of multiple polling outlets.

• Every 25,000 retweets of Russian accounts correlated to a 1% increase in Trump's poll numbers one week later.
• Given the frequency of tweets from Russian accounts, 25,000 retweets would average around 10 retweets per tweet.
• Retweets did not have a similar effect on Hillary Clinton's poll numbers.
• The study also found that 91% of first retweeters of known Russian bots were non-Russian bots, "which suggests that propaganda spread into networks of real U.S. citizens."

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Editor's note: The headline and first paragraph of this story have been updated to clarify that the study suggests a correlation between troll posts and Trump poll numbers.