When and where are Americans happiest? If you go by Twitter, Americans seem to feel the lightest in the early and late hours of the day (based on EST). West coast residents and Floridians seem to stand out as the overall happiest. Between September 2006 and August 2009, over 300 million tweets were analyzed by researchers at Northeastern and Harvard Universities for a research project entitled “Pulse of the Nation: U.S. Mood Throughout the Day inferred from Twitter“.
The mood of each tweet was inferred using ANEW word list. County area data were taken from the U.S. Census Bureau, and the base U.S. map was taken from Wikimedia Commons. User locations were inferred using the Google Maps API, and mapped into counties using PostGIS and U.S. county maps from the U.S. National Atlas. Mood colors were selected using Color Brewer 2.
The resulting cartograms were mapped out the states based on the density of tweets and show the emotional transition of U.S. based tweets throughout the day. A high resolution PDF version (11MB) is also available.