First Monday – Volume 24, Number 7 – 1 July 2019 > Ruck “In 2016, the Internet Research Agency (IRA) deployed thousands of Twitter bots that released hundreds of thousands of English language tweets. It has been hypothesized that this affected public opinion during the 2016 U.S. presidential election. Here we test that hypothesis using vector autoregression (VAR) comparing time series of election opinion polling during 2016 versus numbers of re-tweets or ‘likes’ of IRA tweets. We find that changes in opinion poll numbers for one of the candidates were consistently preceded by corresponding changes in IRA re-tweet volume, at an optimum interval of one week before. In contrast, the opinion poll numbers did not correlate with future re-tweets or ‘likes’ of the IRA tweets. We find that the release of these tweets parallel significant political events of 2016 and that approximately every 25,000 additional IRA re-tweets predicted a one percent increase in election opinion polls for one candidate. As these tweets were part of a larger, multimedia campaign, it is plausible that the IRA was successful in influencing U.S. public opinion in 2016.”