June 21, 2009, addendum from Larry Brilliant:

The demographic transition is real, supported by hundreds of clear studies, but the most important part of it you left out is the “child survival hypothesis” which is now axiom, not theory—that women (and their partners) stop having “replacement” births, “insurance births” and “lottery ticket births” when it is clear from the generation that preceded them that children no longer die before the age of 5.   And the most important reason for this: public health improvements, particularly in sanitation and vaccinations.  Childhood vaccination, which has reduced the under-5 death rate in places like Bangladesh from 50% to under 5% is the second best cure for the population bomb.  The most important intervention:  empowering women, in education and choice, in sexual encounters.

---Larry Brilliant, MD MPH, President Skoll Urgent Threats Fund, senior advisor, Google.org