Irwin M. Stelzer argues that the shortage of organ donors is due to price controls–in particular, the fact that organ donors do not get paid.

if we can begin to think about this issue in a clear-headed way, we might consider the advantages of establishing a genuine, ongoing market in organs. If someone in need of a kidney transplant can locate a donor willing to provide a kidney at a risk doctors find acceptable, what is the argument against allowing consenting adults to strike a bargain that benefits both? That practice is now quite common in many countries, adding years to the lives of the buyers, and undreamed-of wealth to the donors and their families. The fact that the buyers are rich, and the donors poor cannot obscure the fact that both parties are better off when the transaction is completed.

No one can deny that the world would be a nicer place if everyone thought only of how his death could be made useful to others. And if those in charge of allocating the scarce supply of organs were all-wise and uninfluenced by the level of contributions needy recipients have made to their hospitals’ capital drives. But wishing won’t make it so. Neither will appeals to altruism. As for “presumed consent,” it is so close to outright theft that it should never be acceptable. Meanwhile, people die for lack of organs.

This is a controversy of long standing. In the related topic of blood supply, a classic argument against using market approaches is The Gift Relationship, by Richard Titmuss. He said that donated blood is of higher quality than paid-for blood.
For Discussion. Would opening a market in donated organs be a Pareto improvement, or would it make some people worse off?