Statistical Probability That Mitt Romney's New Twitter Followers Are Just Normal Users: 0%

Last week Zach Green of 140Elect, noticed some strange goings-on with Mitt Romney's Twitter account (@MittRomney). Romney's account, which had been averaging around 2,000 to 5,000 new followers a day, gained 141,000 followers in two days. This observation prompted speculation - from Green, Slate, The Huffington Post, CNN, and many others - that the Romney Campaign was buying robot followers, or perhaps (conspiratorially) someone else was buying them to make Romney look bad. But actual analysis of these new followers has been limited to manual observation; many do, indeed, look fake. However, high-profile users can be targets for the algorithms that run bot accounts, and some amount of bogus followers is to be expected. We decided to dig into the data of these new followers to see if they differ statistically from the new followers of other accounts similar in size to Romney. We subjected Barack Obama's account, @BarackObama, to the same analysis. We developed a simple methodology for testing whether a set of followers is likely to be the product of natural user following behavior or bot networks. This test revealed a significant difference between the distribution of followers among the accounts in Mitt Romney's recent spike and that of similar users in our comparison. It strongly indicates that non-organic processes induced Romney's recent surge in followers. We did not find a similar pattern in Barack Obama's recent followers.