'If he is wrong, it should be fairly trivial to find evidence showing why. I personally await this evidence because I find Forrester's model to be sound.' Why

'If he is wrong, it should be fairly trivial to find evidence showing why. I personally await this evidence because I find Forrester's model to be sound.' Why on earth would that be trivial? The social sciences have existed for a hundred years, yet there are few - if any - non-trivial law-like generalisations about the social world.