A false Epistemology that attributes errors, choices, and emergent regularities to a duplicitous cabal that places its own interests above those of the public, rather than to more mundane explanations.
Conspiracism is bad explanation-making. It substitutes intentional villainy for emergent phenomena, systemic failures, and ordinary human error. It is easy to vary — any counter-evidence is reinterpreted as further evidence of the conspiracy.