The world described by Walrasian economics and which is used by free marketeers to justify their policies is a fantasy world. It does not exist nor will it ever exist. It says that under a condition of perfect, complete information where markets exist for all possible types of good and services, where all contracts are sure to be enforced, and where there are no externalities or perfect mechanisms are in place to conteract them, markets will serve to increase overall efficiency given any initial allocation of resource. Even here, however, note that is says nothing about the distribution of those gains. All outcomes are in theory equivalent, even one where you gain almost everything and I gain next to nothing -- an outcome that has been consistently proven to be deemed unjust in ultimatum game experiments in behavioral economics.  

Perhaps these conditions exist in a parallel world described by theoretical physics inhabited by sentient, sociopathic supercomputers. It is not, however, the world you or I live in.

No raindrop believes itself responsible for the flood that follows.