David Haddock and Daniel Polsby, professors at Northwestern University, took up some crucial questions about riots back in 1994.

Day in and day out in any big city, police blotters will reflect the existence of a fairly steady background supply of theft, mugging, arson, and homicide. But this jumble of criminal mischief does not amount to a “riot”; riots are the coordinated acts of many people. If they are coordinated, who coordinates them? Authorities looking for ways to explain why trouble has broken out on their watch sometimes ascribe exaggerated organizational powers to “outside agitators.” While, as we explain, there is definitely a leadership niche in the ecology of a mob, it seems to become important only after the crowd has assembled. Riots are not, as a rule, plotted and scripted affairs.

It would be very difficult indeed to “stage” a riot. A person who set out to do so would encounter a series of difficult challenges. When should the riot be held? Where? How should the participants be notified? Once marshaled, how should they be instigated to behave in a way that would expose them to arrest? Trying to organize a riot as though it were a company picnic would quickly attract the attention of the police. And with the police watching, who would be brave enough to cast the first stone?

How, then, do riots begin?

Those are the questions the professors then attempt to answer.