There has been a long debate about whether speculators are stabilizing or not.We consider a model where speculators have a stabilizing role in normal times,but may also provoke large risk panics. The very feature that makes arbitrageursliquidity providers in normal times, namely their tolerance...

We study a number of large international military conflicts sinceWorld War II where we establish a news analysis as a proxy for theestimated likelihood that the conflict will result in a war. We findthat in cases when there is a pre-war phase, an increase in the warlikelihood tends to decrease...