Correlated Cascades: Compete or Cooperate
In real world social networks, there are multiple diffusion processes which are rarely independent. They usually interact with each other in a competitive or cooperative manner. In this paper, motivated by the reinforcement theory in sociology, we model the adoption behavior of users in social networks by a multivariate marked Hawkes process. According to this model, the intensity of a user to adopt any behavior is modeled by aggregation of behaviors of its neighbors. The type of adopted behavior is also defined probabilistically from the ratio of different product usages among neighbors in which a user can exhibit a competitive or cooperative behavior. In other words, users tend to conduct the mostly adopted behavior in a competitive environment. The resulting inference problem is proved to be convex and is solved by using the barrier method. The advantage of the proposed model is twofold; besides modeling dependent cascades, it also learns the underlying latent diffusion network. Experimental results on synthetic and two real datasets gathered from Twitter, URL shortening and music streaming services, illustrate the superior performance of the proposed model over alternatives.