The effect of media on opinion formation

Our opinions on a social issue can be affected by others’ opinions in social networks and also by various media we are acquainted with. In a modern society, there are many different media we can choose, and we often choose the one that is close to our own political and cultural tastes. We introduce a simple model in which the opinion of an agent is affected not only by other agents in the system, but also by the media. The effect by the media is tuned by a parameter, the media field F in our model, which can either strengthen (for F>0) or weaken (for F<0) the opinion of the agent. As F is varied, we find that our model exhibits three different states: neutral state, consensus state, and polarized state. We observe that a discontinuous transition occurs between the neutral and consensus states, and examine how the finiteness of the system size affects the transition between the consensus and polarized states.