I posted yesterday on the seasonality of casualty trends. An anonymous research professor argues that these are military casualties, and that the civilian casualties show no such trend:
It's not crazy to wonder if the reduction in civilian deaths associated with the troop surge reflects nothing more than a seasonal trend (which is what Drum is concerned about). Iraq Coalition Casualty Count has numbers dating back to March of 2005. Thus, we have civilian casualty counts for the summers of 2005, 2006 and 2007. If their numbers are reliable (and I have repeatedly shown that they are), and if they show that civilian casualties tend to decrease in the summer months compared to the preceding months, then one should take heed of Drum's bottom line:
Bottom line: you should be skeptical of any claims about reductions in violence unless they take seasonality into account. So far, though, I haven't seen any credible claims of reduced violence that even mention seasonality, let alone adjust for it. That should tell you something.
I completely agree. If casualties always drop in the summer, and if they drop by an amount that is roughly proportional to the amount that they have decreased during the troop surge, then one would have to conclude that the surge has not had an appreciable effect on casualties.
On the other hand, if civilian casualties (unlike military casualties) typically increase in the summer, and if they have decreased only in the summer of 2007 (i.e., during the troop surge), then one would have to conclude that the effectiveness of the troop surge is even greater than it appears to be (if, that is, you follow Drum's suggestion). Let's inquire into the matter because we have the data, and we've had it for a long time.