correlation, causation, contagion...,

vice | It's happening in Ukraine, Venezuela, Thailand, Bosnia, Syria, and beyond. Revolutions, unrest, and riots are sweeping the globe. The near-simultaneous eruption of violent protest can seem random and chaotic; inevitable symptoms of an unstable world. But there's at least one common thread between the disparate nations, cultures, and people in conflict, one element that has demonstrably proven to make these uprisings more likely: high global food prices. 

Just over a year ago, complex systems theorists at the New England Complex Systems Institute warned us that if food prices continued to climb, so too would the likelihood that there would be riots across the globe. Sure enough, we're seeing them now. The paper's author, Yaneer Bar-Yam, charted the rise in the FAO food price index—a measure the UN uses to map the cost of food over time—and found that whenever it rose above 210, riots broke out worldwide. It happened in 2008 after the economic collapse, and again in 2011, when a Tunisian street vendor who could no longer feed his family set himself on fire in protest. 

Bar-Yam built a model with the data, which then predicted that something like the Arab Spring would ensue just weeks before it did. Four days before Mohammed Bouazizi's self-immolation helped ignite the revolution that would spread across the region, NECSI submitted a government report that highlighted the risk that rising food prices posed to global stability. Now, the model has once again proven prescient—2013 saw the third-highest food prices on record, and that's when the seeds for the conflicts across the world were sewn.

"I have a long list of the countries that have had major social unrest in the past 18 months consistent with our projections," Bar-Yam tells me. "The food prices are surely a major contributor---our analysis says that 210 on the FAO index is the boiling point and we have been hovering there for the past 18 months."

There are certainly many other factors fueling mass protests, but hunger—or the desperation caused by its looming specter—is often the tipping point. Sometimes, it's clearly implicated: In Venezuela—where students have taken to the streets and protests have left citizens dead—food prices are at a staggering 18-year high.

"In some of the cases the link is more explicit, in others, given that we are at the boiling point, anything will trigger unrest. At the boiling point, the impact depends on local conditions," Bar-Yam says. But a high price of food worldwide can effect countries that aren't feeling the pinch as much. "In addition, there is a contagion effect: given widespread social unrest that is promoted by high food prices, examples from one country drive unrest in others."