Political systems differ along many dimensions, such as the electoral rules, the division of a society into electoral districts, the power of lobbies, the government control of medias, etc. These differences give different politicians to take actions, to spread news, etc., which may have different effects on social cohesion by exacerbating divides along social class, gender, age or national origins, to list just a few. On the other direction, the level of social cohesion and the formal and informal institutions favoring social cohesion may have an effect on electoral outcomes, and, therefore, on the policies that are implemented.