The loss to consumers and producers combined is both the oracle tax and the deadweight loss. So the lack of efficiency is measured by the deadweight loss, and t

The loss to consumers and producers combined is both the oracle tax and the deadweight loss. So the lack of efficiency is measured by the deadweight loss, and the optimal amount of deadweight loss is 0. But then again, what if phones have a negative externality from a society where no one talks to eachother? The oracle tax might be good for society.