Résumé en anglais

We consider a kinetic model describing some mechanisms of opinion formation in the framework of referendums, by allowing that the individuals, who can interact between themselves and modify their opinion by means of spontaneous self-thinking, are moreover under the influence of mass media. After proving the main properties of the model, such as existence of solutions and conservation properties, we study, at the numerical level, both the transient and the asymptotic regimes. In particular, we point out that a plurality of media, with different orien-tations, is a key ingredient to allow pluralism and prevent consensus. The forecasts of the model are compared to some polls related to the Scottish independence referendum of 2014.