During recent interviews with the San Francisco Chronicle, Marlow and Patil described the trends they are seeing.
“Palo Alto, Calif.-based Facebook, for example, has developed a “Gross National Happiness Index” that measures the positive and negative sentiments expressed in status posts. [...]
The team hopes to refine its data mining to answer questions such as how happiness may be contagious or what level of influence different groups of friends have on one another.”

