Modelling the emergence of political revolutions

When do revolutions happen? What are the necessary conditions?
Here are the claims of two influential political theorists.

``a single spark can cause a prairie fire’’
Mao Tse Tung

 “it is not always when things are going from bad to worse that revolutions break out,... On the contrary, it often happens that when a people that have put up with an oppressive rule over a long period without protest suddenly finds the government relaxing its pressure, it takes up arms against it. … liberalization is the most difficult of political arts”
Alexis de Tocqueville (1856)

Is it possible to test such claims? What is the relative importance of levels of perceived hardship and government illegitimacy, oppression, penalties for rebellion, police surveillance, ...?

An important paper in 2002 addressed these issues.
Modeling civil violence: An agent-based computational approach 
Joshua M. Epstein

The associated simulation is available in NetLogo.
It exhibits a number of phenomena that can be argued to be emergent: they are a collective and are not necessarily unanticipated from the model.

Tipping points
There are parameter regimes at which there are no outbursts of rebellion.

Free assembly catalyzes rebellious outbursts
Epstein argues that this is only understood ex post facto.

Punctuated equilibrium
Periods of civil peace interspersed with outbursts of rebellion.

Probability distribution of waiting times between outbursts.
This distribution is not build explicitly into the model which involves only uniform probability distributions.
[Terminology here is analogous to biological evolution].

Salami corruption
Legitimacy can fall much further incrementally than it can in one jump, without stimulating large-scale rebellion.
[I presume the origin of Epstein's terminology is that salami is sliced something thinly... Maybe a clearer analogy would be the proverbial frog in a pot of slowly heated water].

de Tocqueville effect
Incremental reductions in repression can lead to large-scale rebellion. This is in contrast to incremental decreases in legitimacy.