On Twitter a couple of days ago, Adam Elkus called out a recent post on Time magazine’s World blog as evidence of the way that many peoples’ expectations about the course of Syria’s civil war have zigged and zagged over the past couple of years. “Last year press was convinced Assad was going to fall,” Adam tweeted. “Now it’s that he’s going to win. Neither perspective useful.” To which the eminent civil-war scholar Stathis Kalyvas replied simply, “Agreed.”
There’s a lesson here for anyone trying to glean hints about the course of a civil war from press accounts of a war’s twists and turns. In this case, it’s a lesson I’m learning through negative feedback.
Since early 2012, I’ve been a participant/subject in the Good Judgment Project (GJP), a U.S. government-funded experiment in “wisdom of crowds” forecasting. Over the past year, GJP participants have been asked to estimate the probability of several events related to the conflict in Syria, including the likelihood that Bashar al-Assad would leave office and the likelihood that opposition forces would seize control of the city of Aleppo.
I wouldn’t describe myself as an expert on civil wars, but during my decade of work for the Political Instability Task Force, I spent a lot of time looking at data on the onset, duration, and end of civil wars around the world. From that work, I have a pretty good sense of the typical dynamics of these conflicts. Most of the civil wars that have occurred in the past half-century have lasted for many years. A very small fraction of those wars flared up and then ended within a year. The ones that didn’t end quickly—in other words, the vast majority of these conflicts—almost always dragged on for several more years at least, sometimes even for decades. (I don’t have my own version handy, but see Figure 1 in this paper by Paul Collier and Anke Hoeffler for a graphical representation of this pattern.)
On the whole, I’ve done well in the Good Judgment Project. In the year-long season that ended last month, I ranked fifth among the 303 forecasters in my experimental group, all while the project was producing fairly accurate forecasts on many topics. One thing that’s helped me do well is my adherence to what you might call the forecaster’s version of the Golden Rule: “Don’t neglect the base rate.” And, as I just noted, I’m also quite familiar with the base rates of civil-war duration.
So what did I do when asked by GJP to think about what would happen in Syria? I chucked all that background knowledge out the window and chased the very narrative that Elkus and Kalyvas rightly decry as misleading.
Here’s a chart showing how I assessed the probability that Assad wouldn’t last as president beyond the end of March 2013, starting in June 2012. The actual question asked us to divide the probability of his exiting office across several time periods, but for simplicity’s sake I’ve focused here on the part indicating that he would stick around past April 1. This isn’t the same thing as the probability that the war would end, of course, but it’s closely related, and I considered the two events as tightly linked. As you can see, until early 2013, I was pretty confident that Assad’s fall was imminent. In fact, I was so confident that at a couple of points in 2012, I gave him zero chance of hanging on past March of this year—something a trained forecaster really never should do.
Now here’s another chart showing my estimates of the likelihood that rebels would seize control of Aleppo before May 1, 2013. The numbers are a little different, but the basic pattern is the same. I started out very confident that the rebels would win the war soon and only swung hard in the opposite direction in early 2013, as the boundaries of the conflict seemed to harden.
It’s impossible to say what the true probabilities were in this or any other uncertain situation. Maybe Assad and Aleppo really were on the brink of falling for a while and then the unlikely-but-still-possible version happened anyway.
That said, there’s no question that forecasts more tightly tied to the base rate would have scored a lot better in this case. Here’s a chart showing what my estimates might have looked like had I followed that rule, using approximations of the hazard rate from the chart in the Collier and Hoeffler paper. If anything, these numbers overstate the likelihood that a civil war will end at a given point in time.
I didn’t keep a log spelling out my reasoning at each step, but I’m pretty confident that my poor performance here is an example of motivated reasoning. I wanted Assad to fall and the pro-democracy protesters who dominated the early stages of the uprising to win, and that desire shaped what I read and then remembered when it came time to forecast. I suspect that many of the pieces I was reading were slanted by similar hopes, creating a sort of analytic cascade similar to the herd behavior thought to drive many financial-market booms and busts. I don’t have the data to prove it, but I’m pretty sure the ups and downs in my forecasts track the evolving narrative in the many newspaper and magazine stories I was reading about the Syrian conflict.
Of course, that kind of herding happens on a lot of topics, and I was usually good at avoiding it. For example, when tensions ratcheted up on the Korean Peninsula earlier this year, I hewed to the base rate and didn’t substantially change my assessment of the risk that real clashes would follow.
What got me in the case of Syria was, I think, a sense of guilt. The Assad government has responded to a legitimate popular challenge with mass atrocities that we routinely read about and sometimes even see. In parts of the country, the resulting conflict is producing scenes of absurd brutality. This isn’t a “problem from hell,” as Samantha Powers’ book title would have it; it is a glimpse of hell. And yet, in the face of that horror, I have publicly advocated against American military intervention. Upon reflection, I wonder if my wildly optimistic forecasting about the imminence of Assad’s fall wasn’t my unconscious attempt to escape the discomfort of feeling complicit in the prolongation of that suffering.
As a forecaster, if I were doing these questions over, I would try to discipline myself to attend to the base rate, but I wouldn’t necessarily stop there. As I’ve pointed out in a previous post, the base rate is a valuable anchoring device, but attending to it doesn’t mean automatically ignoring everything else. My preferred approach, when I remember to have one, is to take that base rate as a starting point and then use Bayes’ theorem to update my forecasts in a more disciplined way. Still, I’ll bring a newly skeptical eye the flurry of stories predicting that Assad’s forces will soon defeat Syria’s rebels and keep their patron in power. Now that we’re a couple years into the conflict, quantified history tells us that the most likely outcome in any modest slice of time (say, months rather than years) is, tragically, more of the same.
And, as a human, I’ll keep hoping the world will surprise us and take a different turn.