One standard objection is that individuals could be “coerced” into selling their organs. But this argument is exactly backwards. To find coercion, look no further than the family situation where one member is an organ match for a sibling or a child, but has serious qualms about taking the risk in question. Now money or in-kind benefits cannot be offered to offset that risk. So the full array of nonstop family pressures can be imposed in order to get the reluctant relative to change his or her mind. But in an open market, the potential of thousands of unrelated donors makes it both impossible and unnecessary to bring subtle pressures to bear on these strangers. Coercion is not an inherent consequence of voluntary exchanges. Rather, it is a far greater risk when only uncompensated transfers can be allowed.

A second objection is that the voluntary market will discriminate against the poor who do not have the means to pay. To this point, two responses are in order. First, right now rich people can influence the UNOS allocation process to work their way up the queue. Richer people have more contacts and more resources to spend on getting themselves on, if necessary, multiple queues. Worse still, there are all sorts of opportunities to divert cadaveric organs to favored recipients, as major transplant centers can keep harvested organs for their own patients by claiming that their condition renders them unfit to be transferred elsewhere. No system that allocates huge benefits for zero or below market price will be immune from influence, whether we are talking about rent-controlled units in Manhattan or unassigned kidney organs, whose donor, often young and poor, receives not one cent from the successful transfer.

Second, money does not have to be an obstacle to getting a kidney transplant. If we redirect some subsidy funds away from dialysis treatments, people who cannot afford to pay for an organ could still have the opportunity to receive a transplant.