The Collective Dynamics of Smoking in a Large Social Network
Roughly 44.5 million adults were smokers in the United States in 2004,1 and smoking remains the leading preventable cause of death,2 with 440,000 deaths annually.3 Nevertheless, the prevalence of smoking has declined from 45% to 21% over the past four decades.4 Past studies have documented the impact of dyadic social ties on the initiation and cessation of smoking, primarily in young people.5,6 However, the extent to which smoking depends on how people are embedded in a social network and the extent to which smoking behavior transcends direct dyadic ties are not known. Since diverse phenomena can spread within social . . .