Places to begin:

• http://www.copenhagenconsensus.com/publication/post-2015-consensus-conflict-and-violence-assessment-hoeffler-fearon
• http://www.slate.com/articles/news_and_politics/foreigners/2014/12/the_world_is_not_falling_apart_the_trend_lines_reveal_an_increasingly_peaceful.html

Neglectedness

From the CCC summary:

In the broad area of building stable and peaceful societies, the UN HLP has identified several areas where the benefit/cost ratio may be very high, and that have been relatively neglected by the development community to date. There are areas where the current economic and social costs are plausibly quite large, and where the amount of attention is very small in comparison to other areas such as health, education, and governance reform.