Here's an interesting case of a woman attempting to sell her child. It is instructive to see how what is effectively legal behavior is the result of at least three factors: real law (case law), statutes and public opinion.
Rothbard has opined on the issue of selling one's own children and comes down firmly on the side that selling your children is a fundamental right. With some caveats (mainly that genetic relatives have a first right of refusal), I agree. For example, in this case, if the grandmother wants to take on the care of the child, the parent should not be able to insist on the sale. This is because the child is not the parent's property, only the parenting rights are.
Transfer of parenting rights is not like title transfer to an automobile. The power to transfer parenting rights is limited by the legitimate interests of other genetic relatives in ensuring the welfare of the child. These interests cannot be ignored and this means that a parent may not rightfully transfer his or her parenting rights to a genetic stranger over the objections of a genetic relative who is offering to take over caring for the child.
But for those who are in sufficiently desperate circumstances (perhaps they don't even have any living relatives who could object to the sale, let alone help them financially) selling children may be an improvement of the lives of all involved - the buyer, the child, the parent(s), and the remaining siblings. As human beings we naturally attach an emotional stigma to willingly abandoning one's own children. It's good that we feel that way... this means we'll only resort to such desperate measures when they really will result in a better situation.
What about contractual reproduction? In fact, we actually already have contractual reproduction; it's called marriage. In the case of prior contract, genetic relatives do not have a legitimate interest in the parenting rights because the child is not yet born.
Let's say John wants a baby and he's willing to pay Mary to conceive it for him. The law treats the situation differently depending on whether the baby has John & Mary's DNA (standard conception, perhaps mediated through a fertility clinic or sperm bank), only Mary's but not John's DNA (adoption), John's but not Mary's DNA (surrogacy) or neither John's nor Mary's DNA (surrogacy&adoption).
The genetic relatives of the baby in any of these four instances would not have a legitimate right to prevent John and Mary (or some other combination) from copulating and conceiving the natural way. Hence, they do not have a right to prevent them from doing so through artificial means. But until the baby is born, the genetic relatives have no legitimate interest in the child because it simply does not exist. Hence, John and Mary (and the other concerned parties) may legitimately contract to transfer parenting rights of an as-yet-unborn child without interference or impediment by genetic relatives.
But if the child is born in the absence of any contract regarding the transfer of its parenting rights, then the parenting rights of the child will fall under the purview of the common law. Here, the genetic relatives do have a legitimate interest in the survival of the child by virtue of kinship and retain a right-of-first-refusal. California has some of the most liberal laws in regard to transfer of parenting rights.
Clayton -
The power to transfer parenting rights is limited by the legitimate interests of other genetic relatives in ensuring the welfare of the child.
I have a feeling that the kind of cultural winds that would blow away the stigma of selling babies would also knock down our conception of the family (and I'm very impressed with my own imagery here). The special status we award to genetic relatives is probably some sort of product of our place and time, with a healthy dose of biology, but since the same could be said about the taboo of selling children, there is no reason to act as if in the absence of one, the other would necessarily hold true.
they said we would have an unfair fun advantage
+1 to mikachusetts for not fearing change in the family unit.
The family unit has already changed a great deal just within human history and will continue to change. However, such change should be spontaneous and not imposed. If history is any guide, the changes that actually come about are unlikely to fit any preconceived picture of social order.
There is nothing to see here.
In true anarchy, selling a child would be synonymous with giving a child up for adoption.