Even in an unstable gathering, the first perpetrator of a misdemeanor is at risk if the police are willing and able to zero in on him. Thus, someone has to serve as a catalyst—a sort of entrepreneur to get things going—in Buford’s account usually by breaking a window (a signal that can be heard by many who do not see it). In civil rights, anti-war or anti-abortion marches, it is probably pretty common to find participants eager to expose themselves to arrest in exchange for the chance to optimize the desired impact of their protest. This sort of self-sacrifice is certainly rare in ordinary riots, where potential rioters’ behavior is consistent, we suppose, with something like the following calculation: “If somebody else gets the riot started, I can participate without much risk. But if I stick my neck out and nobody follows, I’ll be the only one arrested. So I’ll wait for somebody else to go first.” If every would-be rioter reasoned thus, nobody would cast the first stone, and the riot would not ignite. This is a typical free-rider problem, as economists have called it. It is usually sufficient to prevent riots from occurring, even where there is a plentiful supply of disposed participants. Riots await events that surmount the free rider problem. The entrepreneur will throw the first stone when he calculates that the risk that he will be apprehended for doing so has diminished to an acceptable level.
