Optimal Organization of Surrogacy Contracts and Underinvestment

We develop a theoretical model of commercial gestational surrogacy in which a childless couple approaches a prospective surrogate, who is willing to gestate for the couple. We use a Principal-Agent framework with continuous effort to argue the following: in presence of limited liability of the surrogate, provision of optimal incentives (under non-contractible effort) is not feasible. Hence, a surrogate facing low outside option and having limited wealth is always found to put in sub-optimal care for the fetus. Put differently, the surrogate cannot be made a residual claimant (cannot be entitled with custody rights of the fetus) and therefore eliciting first best care is never optimal. But this result dramatically changes when the model is cast in discrete effort where inefficiency is likely only when the surrogate faces low outside option whereas we get multiple efficient contracts for higher outside option. Moreover, we see first-best efficient contracts may be implemented even without full transfer of custody rights to the surrogate.