In conversations with friends who had read Steven Pinker's book
The Better Angels of Our Nature and how we have less violence now. The implications of this view and others along these lines is that things are getting better and we are not aware of this trajectory, in part because of the amount of information that we now have easily available to us. The measures used justify the claims. However, it seems to me that there is a general pattern with measures, in this as well as other domains. We create measures that justify our narrative. In this case it justifies a sense of optimism which seems to me is part of American culture. With any metric we choose, we leave out the larger part of the system we are talking about as that does not fit the narrative we want those measures to justify. In this case the measures declining violence leave out the measure of species extinction, destruction of ecologies, measures of pollutions, .... These are all forms of violence against the larger system of which we are a part.