Evidence of incentives working, I think.

In general I think that the overall framework suffers from the (very big, IMHO) problem of ignoring the interests of various people and the consequent incentives.People in real life are not impartial beings of pure rationality -- they will and routinely do filter the evidence, misrepresent it, occasionally straight out invent it, all for the purpose of advancing their interests. And that's on top of people sincerely believing what is useful/profitable for them to believe.