Last week, Notre Dame Coach Brian Kelly described the Michigan-Notre Dame game as not “one of those historic, traditional Notre Dame rivalries.” These comments helped invigorate discussions, newspaper columns, and College GameDay signs debating the magnitude of the Michigan & Notre Dame rivalry.
Rather than listen to “experts” tell us about the significance of the game (or fabricate memories of the game), we decided to use Twitter to study how much people cared about the game in South Bend, IN and Ann Arbor, MI. The setup for our study was fairly simple. Using data from Topsy Pro Analytics, we were able to examine tweets originating from South Bend and Ann Arbor. We compiled a list of words that could be used to describe Notre Dame (e.g. “Notre Dame”, “ND”, “Fighting Irish”) and a list of words that could be used to describe Michigan (e.g. “Michigan”, “UM”, “MICH”, “UMICH”). We then collected all tweets that mentioned any of the Notre Dame related words and originated from Ann Arbor. We also collected all tweets that mentioned any of the Michigan related words and originated from South Bend. We believe that these tweets are capturing the level of “rivalry” that each campus has toward the other campus*.
For the game played on September 7, 2013 in Ann Arbor, we looked at tweets on September 5th and 6th (pre-game). We also examined tweets on September 8th (post-game). We computed the Twitter Share of Voice for tweets about Notre Dame in Ann Arbor and for tweets about Michigan in South Bend for both Pre and Post-game. As an illustration, to compute Twitter Share of Voice for Notre Dame related tweets in Ann Arbor, you simply divide the number of tweets that mention Notre Dame in Ann Arbor by the total number of tweets in Ann Arbor. We believe that this Share of Voice metric helps control for the relative sizes of Twitter bases in the two cities.
The results from the 2013 game are very interesting. Pre-game, the Twitter Share of Voice in Ann Arbor for Notre Dame related tweets was 60% higher than Twitter Share of Voice in South Bend for Michigan related tweets. This implies that people in Ann Arbor cared more about the game (at least on Twitter) than people in South Bend. Post-game, the Twitter Share of Voice went up by 57% in Ann Arbor. The sentiment (ratio of positive to negative tweets) of the post-game tweets also rose by 40%, whereas there was no change in sentiment in South Bend (Michigan won the game). We could interpret this as Notre Dame fans were relatively unaffected by the loss.
Perceptive Michigan and Notre Dame fans could argue that these results are skewed because the game was played in Ann Arbor. We have excluded tweets from the day of the game to try to correct for any game site effects. However, to get a better understanding of the “rivalry”, we performed a similar study of the 2012 game which was played in South Bend. Even though the game was played in South Bend, the pre-game Twitter share of voice was 18% higher in Ann Arbor. The Notre Dame victory only created a 14% increase in the post-game share of voice in South Bend, and a 23% increase in tweet sentiment. Thus, looking at data from the past two years, there seems to be an asymmetry in this “rivalry”. That is, it seems Michigan cares a lot more than Notre Dame.
Mike Lewis & Manish Tripathi, Emory University 2013.
*Obviously, both of these universities have alumni all over the world. We are limiting our study to South Bend & Ann Arbor because we believe this (1) captures current students and (2) is the cleanest way to separate out the two fan bases.