Abstract

Will we have more or fewer deadly wars in the new few decades? Until recently it has been very hard to say much about what makes wars more more frequent or deadly. It doesn't seem to have much to do with levels or changes in population density, whether the economy is booming, how dependent a nation is on trade, or on the number of great powers around. Wars seems only weakly if at all correlated across space and time, seeming for example to be a bit more deadly when they are less frequent. More democratic nations may if anything be more likely to fight wars, though perhaps they less often fight each other, and perhaps join wars more often just after an election [1].