Estimating the intensity of conflict in Iraq
Since 2003 several Web sites have appeared that track the number of deaths of coalition personnel in the current Iraq conflict. The paper proposes the use of a recently developed multiscale variance stabilization method (the data-driven Haar-Fisz transform) to obtain good estimates of the mean intensity of deaths and demonstrates its statistical advantages over both the running mean (which is currently used on some Web sites) and also the Box-Cox transformation. The paper analyses both the number of deaths due to all causes and also due to hostile actions between June 2003 and March 2006. In both cases it appears that the marginal variance of both time series is an increasing function of the marginal mean. Further, although our estimates exhibit peaks that are related to local increases in intensity of conflict there appears to be a clear underlying increase in intensity of conflict during the conflict but with a decline and levelling off since June 2005. The paper also proposes a tentative inverse relationship between deaths due to non-hostile actions and deaths due to hostile actions. Copyright (c) 2008 Royal Statistical Society.