Threshold Models of Collective Behavior (Granovetter. 1978)

The previous post made me think of a great paper on threshold models that I read some years ago. In very brief, a person's decision whether to riot or not (for example in Egypt) depends on what everyone else is doing. Some will start even if there is no one else, other need a critical number - a theshold. This threshold is assumed to be distributed to some probability distribution; it is thus different for different people. Interestingly, the outcomes may diverge largely even if the initial condition of threshold may only differ very slightly. I think this is still the best summary of his argument though:

Please watch this. This is absolutely brilliant!

Reference:
Mark Granovetter. 1978. Threshold models of collective behavior. The American Journal of Sociology.