E Ferrara, O Varol, F Menczer and A Flammini
ACM Conference on Online Social Networks (COSN’13), 2013.
Trending topics reflect the conversations that grab collective attention on online social media. They are continually changing and often reflect exogenous events that happen in the real world.
Trends are localized in space and time as they are driven by activity in specific geographical areas that act as sources of traffic and information flow. Taken independently, trends and geography have been discussed in recent literature on online social media; although, so far, little has been done to characterize the relation between trends and geography.
Here we investigate more than eleven thousand topics that trended on Twitter in 63 main US locations during a period of 50 days in 2013. This data allows us to study the origins and pathways of trends, how they compete for popularity at the local level to emerge as winners at the country level, and what dynamics underlie their production and consumption in different geographical areas.
We identify two main classes of trending topics: those that surface locally, coinciding with three different geographical clusters (East coast, Midwest and Southwest); and those that emerge globally, whose locations coincide with the main air traffic hubs of the country.
Travel hubs act as trendsetters, generating topics that eventually trend at the country level, and driving the conversation across the country. This poses an intriguing parallel with the spread of diseases: Does information travel faster by airplane than over the Internet?