Why Conspiracies Are Hard To Pull Off

For every added conspirator, the chances of success fade:

This can be formulated in a model.  Let n be the number of conspirators and let p= probability that a single conspirator will not cause failure, either through disloyalty or incompetence.  Then

equation

Where A is a proportionality constant.  “Effectiveness” is a nebulous concept because I haven’t specified the conspiracy.  You can think of it as some measure of success appropriate to a particular conspiracy.  The simplest case is to assume Effectiveness is proportional to the number of conspirators, but one can imagine alternatives.

So for a typical example, A=1/10 and p=.75.  These give a Chance of Success (for Effectiveness=1) of 6%.  If the conspirators are in a Prisoner’s Dilemna situation where it’s advantagous to turn on the others, then p=.1 and the Chance of Success is equation, which nicely explains why conspiracies rarely work.