»For a riot to begin, it is necessary but not sufficient that there be many people who want to riot and who believe that others want to riot too. One more hurdle has to be overcome. 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 – (...) usually by breaking a window (a signal that can be heard by many who do not see it). (...) 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. The risk of arrest declines as a function of two variables – the size of the crowd relative to the police force available to control it, and the probability that others will follow if somebody leads.« [The Cato Journal, Vol. 14 No.1]

Und die Ableitung dieser Funktion?