At a Frankfurt-based conference this week, Professor Armin Falk from Bonn University explained his ideas on the so-called soft paternalism. You can find the full audio file as well as an interview (German only) online.
One of his examples is organ donation. Referring to a paper by Johnson and Goldstein in Science, Falk pointed to the huge difference in effective consent rates between opt-in and opt-out countries:
Effective consent rates by country // source: Science vol. 302
Consider that every policy must have a no-action default, and defaults impose physical, cognitive, and, in the case of donation, emotional costs on those who must change their status.
Our data […] suggest changes in defaults could increase donations in the United States of additional thousands of donors a year. Because each donor can be used for about three transplants, the consequences are substantial in lives saved.
Swiss Economist 