The authors write that this may be the largest wave of nonviolent mass movements in world history. What comes next? Social media has made mass protests easier to organize — but, perhaps paradoxically, harder to resolve.

Several prominent accounts suggest that democratic transitions are more likely to take place when opposition to the incumbent regime is led by certain social groups. The authors further develop the argument that opposition movements dominated by industrial workers or the urban middle classes have both the requisite motivation and capacity to bring about democratization. Their study shows that when further differentiating the groups and accounting for plausible alternative explanations, the relationship between industrial worker campaigns and democratization is very robust, whereas the evidence is mixed for middle-class campaigns.

The authors write that the success of mass protests depends on who is doing the protesting. For example, when industrial workers mobilize mass opposition against a dictatorship, democratization is very likely to follow.