The explosion of interest in stem cell research raises a raft of controversial policy questions. When should human embryos be used to create stem cells? Should cloning be outlawed? Should egg and tissue donors be paid? Should we allow scientists to patent stem cells? Is the government entitled to a portion of the revenue from stem cell technology created with public funds? How should the regulators and courts balance the competing goals of access to revolutionary treatments and protection of the public from unknown risks?

Russell Korobkin, with contributions from Stephen R. Munzer,...