“The Copenhagen Consensus Center… puts the global costs of violence, excluding conflicts, at $9.5 trillion a year, equivalent to around 11 per cent of world GDP” (New Scientist, February 9, 2017). Encouragingly, “VIOLENT crime is on the retreat in most advanced economies. The latest US figures, for 2013, show that murder rates are lower now than in the early 1960s. In the same year, homicides in Japan hit a post-war low.