Some say the global unrest is all of a piece. The financial writer Felix Salmon, for instance, argues that we’re facing a global crisis of institutional legitimacy. “The glue holding society together is dissolving,” he writes, “whether it’s made of fear or whether it’s made of enlightened self-interest.”

But perhaps we should give the world’s political systems a bit more credit. The past few years have been something of a stress test for public institutions. This is the most severe economic crisis the world has seen for the better part of a century. The public is angry, and governments are unusually impotent. Just as financial stress tests are used to see whether banks can survive even when everything is going wrong, this economic stress test is demonstrating which political systems can survive when everything is going wrong. And most of them are surviving. Some might say too many of them are surviving.

Which isn’t to say they are working. Many of our political systems are performing terribly. Voter anger has led to gridlock, and gridlock is standing in the way of effective lawmaking. Indeed, Morgan Stanley warns that we’re facing a “policy-induced slowdown.”

But underperforming isn’t the same as dissolving. And political systems are more robust to weak economic growth than is commonly thought.

Jay Ulfelder is a political scientist who specializes in state failure. He and the University of Texas’s Patrick Brandt just completed one of the largest and most statistically rigorous studies ever conducted on the relationship between economic growth and political instability. “What we see in the data,” he says, “is that there is a connection between social unrest — riots, protests, etc. — and slower economic growth or rising food prices. But that kind of unrest and those broader economic changes don’t necessarily lead to the kind of dramatic instability at the regime level that people have in mind when they’re worrying about this.”

What political scientists have found, in other words, is that economic stress does lead to social unrest. Slow the economy down and you can expect a rise in riots, protests, coup attempts and the like. But that type of civil unrest doesn’t do very much to predict whether a regime falls. In most cases, it’s a show of unhappiness more than an existential threat.

It’s hard to get a handle on this from watching riots unfold on TV. Protests that can presage the fall of an Arab government look a lot like those that are mostly just a headache for European politicians. Anger is anger is anger. But a mostly peaceful display of frustration in Ireland is a healthy sign that its democracy is working, as are efforts by both parties in America to channel public ire over the economy into gains in the next election. Conversely, popular protests against a dictatorship can be a sign that a system is in collapse. The differences occasionally get elided in the popular conversation.

“We have to know what we’re talking about,” says John Sides, a political scientist at George Washington University. “Are we talking about political parties losing? Are we talking about a hegemonic party in a mostly democratic state actually being overthrown or unseated? Are we talking about overthrowing a dictatorship or a repressive regime?”

Even the most extreme cases might yet herald less change than we hope. Take, for instance, Egypt, where protesters forced a succession, but where it’s not yet clear they forced a regime change. Or Libya, where it looks like an autocrat will fall, but where it’s hard to know whether he will be replaced by a democracy.

Sometimes, a system that seems to be breaking down is actually demonstrating an unexpected form of resilience. Ulfelder, for one, isn’t very optimistic about the Arab uprisings. “I think it’s still an open question how successful they will be,” he says. “Think back to the end of the Soviet Union. There was a euphoric phase at the beginning when it looked like revolutions were succeeding and dictators were toppling and something very radical was happening. Fast forward 10 years, though, and it had become clear that a lot of the changes were less radical than we’d hoped. My base line expectation is that the results of this wave will be similarly mixed.”