I think you need verifiable pre-commitment, not just communication—in a free-market economy, enforced property rights basically function as such a pre-commitment mechanism. Where pre-commitment (including property right enforcement) is imperfect, only a constrained optimum can be reached, since any counterparty has to assume ex-ante that the agent will exploit the lack of precommitment. Imperfect information disclosure has similar effects, however in that case one has to “assume the worst” about what information the agent has; the deal must be altered accordingly, and this generally comes at a cost in efficiency.
I think you need verifiable pre-commitment, not just communication—in a free-market economy, enforced property rights basically function as such a pre-commitment mechanism. Where pre-commitment (including property right enforcement) is imperfect, only a constrained optimum can be reached, since any counterparty has to assume ex-ante that the agent will exploit the lack of precommitment. Imperfect information disclosure has similar effects, however in that case one has to “assume the worst” about what information the agent has; the deal must be altered accordingly, and this generally comes at a cost in efficiency.