A New Scientist article looked at the rates of human organ donation in various countries (see chart) and argued against the presumption that higher rates are due to national policies of "presumed consent" (a person is in the donor pool unless he opts out) vs "informed consent" (a person is out unless he opts in).
The writer theorized (based on experiences in the world's donation-leader, Spain) that rather than the law, high rates are the result of "efficient transplant coordination and the way families are approached," and went on to describe some of those factors.
All well and good and believable.
But for me, a huge question remains: What's going on in Japan??