Coups d’etat don’t happen as often as they used to, but they do still happen. In the past few year, coups have toppled leaders in Honduras, Niger, and arguably Egypt, while coup bids have fizzled in Guinea-Bissau (twice), Democratic Republic of Congo, Madagascar, and, less than a year after the aforementioned success, Niger. Meanwhile, just this morning, we’re hearing fresh rumblings of a possible coup in Pakistan, which last saw the military openly seize power in 1999. (Whether it’s ever really taken its hands off the levers of power at any point in Pakistan’s history is another matter.)

The persistence of coups is a bit of a puzzle, because coup attempts are typically costly to their perpetrators in at least two ways.

1. Most coup attempts fail. From 1955 to 2008, half of all coup bids worldwide failed (158 of 316). As the chart below shows, the failure rate has been much higher in the past two decades than it was in earlier years. And these are just the coup bids that make it all the way to an overt attempt. If our tally also included all of the plots that were uncovered and foiled before they could be put in motion, the failure rate would be much higher. If coup attempts usually fail, and the punishment for a failed coup is often imprisonment or death, then coup bids would seem to be a pretty risky gamble for their plotters.

2. Coups take a toll on the economy. The figure below plots the estimated impact of a successful coup on a country’s GDP growth rate over the several years following the coup event (data geeks: see the technical notes at the end of this post for details on the method used to derive these estimates). The impact is substantial: on average, a couple of percentage points knocked off the growth rate in the year of the coup and another point or so the following year. Expected growth rates resume a few years after the coup, and there even seems to be something of a rebound effect several years down the road, but three or four years is a long wait in political time. This knock on the GDP growth rate matters for coup plotters because if they succeed, they’re liable be blamed for the damage done (Pakistani generals, take note!).

In light of these facts, it’s hard to understand why coup plotters keep trying, even if they are trying less often. To attempt a coup, you’ve either got to be ignorant of these facts or to consider them irrelevant to your particular situation. You might consider them irrelevant because you’re exceedingly optimistic about your own coup’s chances for success, as behavioral psychology suggests many military and political leaders will be. Alternatively, you might expect your attempt to fail but still think it’s worth a try because you believe that success will produce large private benefits (like the opportunity to loot the state treasury) or non-economic public benefits that will reflect well on you and your co-conspirators (like liberation from an awful tyrant, or defense against public disorder).

My hunch is that all of these forces–ignorance, optimism, greed, and benevolence–factor into the decision-making behind many coup attempts. We’ll never really know for sure, because even first-hand accounts of plotters’ motivations are highly unreliable. What we can say with some confidence, I think, is that people are going to keep trying anyway.

Technical Notes

The figures and charts in this post are based on coup event data compiled by Monty Marshall at the Center for Systemic Peace. You can find them here, under the Polity IV heading.

To estimate the impact of successful coups on GDP growth, I first used “coarsened exact matching” to pre-process a time-series cross-sectional data set of all countries worldwide for the period 1955-2008. Country-years were matched on several risk factors for successful coups, including infant mortality rates, degree of democracy (Polity scores, quadratic), recent coup activity, and a marker for the post-Cold War period. After matching, I used Zelig to estimate the average “treatment effect” for successful coups. The values used in the plot above are the medians from six iterations of this drill, one for each year away from the coup event. The GDP growth data are from the World Bank’s World Development Indicators.