Thailand has been engulfed in political crisis for a week now, with street protests pushing to outright topple the government of Prime Minister Yingluck Shinawatra. The crisis is especially serious given that Thailand has experienced more coups d'état than any other country in contemporary history. Scholars sometimes describe the era beginning in 1932 and running up through today as Thailand's "coup season." Since 1932, Thailand has endured an astonishing 11 successful military coups, as well as seven attempted coups.

Thailand-watchers are divided on whether this crisis appears likely to spark successful coup number 12. Joshua Kurlantzick of the Council on Foreign Relations says it could. The Economist's writer in Bangkok argues a coup is unlikely at this point.

To better understand why Thailand has so many coups, whether we should worry about another one and what makes countries susceptible to coups in general, I talked to Jay Ulfelder, a political scientist who specializes in state failure and also works as a consultant. While not a Thailand expert, Jay has done lots of research on coups and the risk factors that can lead to them. A lightly edited version of our e-mail exchange follows.

WorldViews: What are some of the most important factors that make countries susceptible to coups? Does Thailand appear to have those?

Jay Ulfelder: The most informative factors in thinking about coup risk are a country's wealth, its form of government, and the recent occurrence of coup activity. Coup attempts very rarely happen in countries that are rich, either fully dictatorial or fully democratic, and have no coup activity in the recent past. Almost all coup attempts, successful or failed, occur in countries that are relatively poor and have political regimes that mix features of autocracy and democracy.

These mixed regimes are especially susceptible to coups when politics within them is sharply polarized, as it has been in Thailand for nearly a decade now.

Coup activity also tends to cluster, so countries that have seen one or more attempts in the past five years are several times as likely to get hit by another than countries that have been coup-free for a while. We saw this pattern recently in Mali and Egypt, among other places.

Thailand has some important risk factors but not others, so it winds up in the middle of the global pack in terms of risk. It has a mixed regime with sharply polarized politics, but it's now a middle-income country, and it's managed to muddle along without another coup attempt since 2006. Of course, coups are very rare events -- nowadays, we usually only see a handful of attempts worldwide each year -- so even being in the middle of the pack translates into a very low likelihood, like less than 5 percent.

WorldViews: You and others have suggested that Thailand's protesters, led by opposition political figure Suthep Thaugsuban, appear to be trying to spark another military coup. How likely does it look that they'll be successful?

Jay Ulfelder: An annual statistical forecast gives us a good starting point for thinking about whether or not the [opposition] Democrat Party's attempt to provoke a coup will succeed, but it would be silly to ignore the new information we get as politics unfolds over the course of that year. The fact that Suthep Thaugsuban and co. have managed to manufacture a crisis from which a coup might offer a (temporary) exit suggests that the probability of an extra-constitutional exit for Prime Minister Yingluck Shinawatra is certainly higher than it was several weeks ago.

I'm not an expert on Thai politics, and I have no inside information on what the relevant players are considering, so it's hard for me to say with much confidence just how much that risk has increased. As a generalist who knows the statistics, though, I would guess that the crisis will resolve without a full-blown coup attempt, by which I mean the removal of [Yingluck] and the Pheu Thai Party from power by extra-constitutional means involving the use or threat of force by political or military insiders.

WorldViews: Thailand has had more coups in the recent past than perhaps any other country. Is there something particular about Thailand that has made it so historically susceptible to coups?

Jay Ulfelder: Yes, Thailand is unusual in this regard. I'll leave it to the country experts to speculate on why that's the case, though. I don't see anything in the historical data on risk factors that makes Thailand stick out as much as its coup-prone history suggests it should. That's a challenge for a future round of model-building.

WorldViews: Does Thailand's history of coups, in itself, make future coups more likely?

Jay Ulfelder: Yes, as noted in my response to your first question. As for why, I wrote a blog post about the "coup trap" last year. As I said there, my statistical models aren't designed to test specific hypotheses about why coups recur, so I don't want to make any strong statements about that.

I will say, though, that the patterns highlighted by these and many similar models strengthen my own belief that confidence plays a crucial role in politics and political stability. Whether they succeed or fail, coup attempts often disrupt established relationships among political elites. These disruptions increase elites’ uncertainty about the intentions of their potential rivals, and the proximity of the last attempt may lead them to overestimate the likelihood of the next one.

In a kind of self-fulfilling prophecy, this intensification of uncertainty strengthens incentives to try to seize power before the other guys do. Once trust has dissolved, no one wants to be the sucker who keeps cooperating while the other guys are all planning to fink.