Although I am by no means an expert in population, there are a number of interesting studies which show a deep statistical correlation between increased income and decreased birth rates over time. Higher income families and high income societies have significantly lower population replacement rates.

That being said it also seems that there is an immediate correlation between suddenly higher income and a individual family unit also increasing (i.e. when a family gets a sudden, large increase in income they will generally also increase their family size at that time).

So, with all of that being said, since in the words of the Gates this is a "bet", we could also potentially bet that by increasing the number of middle class individuals within a given population we will also see an overall increase in birthrate among those populations.

This[1] suggests that fighting poverty is a pretty effective way to fight overpopulation. Most rich countries are reproducing well below replacement rates, and as poor countries become rich their average fertility reliably plummets. There are number of theories as to why, but one of the more compelling ones is that peoples' relationship to their children changes when they can be reasonably certain that all of those children will survive to adulthood. If that's correct, then public health initiatives may provide an even more direct impact on wide-scale population control.

[1]: http://en.wikipedia.org/wiki/Demographic-economic_paradox

It turns out that most countries go into negative growth once they hit a certain level of development/stability/richness. The solution to the problem is therefore, obviously, to ensure that all countries reach this level.

I remain a perpetual technological optimist, we'll solve this problem as well.

Btw, it's very hard not to read your comment like "wouldn't it be better for everyone if all these poor people just died off...?"

I really do not want to come across as a proponent of genocide, but I do not know how to phrase it any better (not my first language sorry)

I understand, and I honestly don't know how to phrase it better either.

Easy free birth control and family planning will reverse that trend quickly. Look at Iran for example:

https://en.wikipedia.org/wiki/Family_planning_in_Iran

Interesting, lots of downvotes and several upvotes (saw it jump up and down several times). I guess this splits our community. Too bad the point is apparently deemed inappropriate for discussion. I would have enjoyed to learn what smart people here think we should do about this.

It's not inappropriate for discussion, it's just wrong. People who are rich and healthy don't have kids above replacement rates. We don't know why but we've observed the effect within countries, between countries, and across a broad range of cultural and religious groups. Economic improvement and public health aren't in opposition to population control measures, they are population control measures.

The correlation doesn't seem to hold at the high end, and much of the data in the western world confounds population growth due to fertility (still low) with population growth due to immigration (which has upticked across the board in recent years). As far as I know, though, the effect is still strong in the delta range that the Gates foundation is targeting.

Well, I wish what you were saying was true, but recent data show that it is not, see for example [1]

Furthermore, depletion of resources is not a simple numbers game: a rich person produces several orders more CO2 than a poor person to name just one example. If Africa becomes wealthy enough to come anywhere close to Americans for meat consumption there is going to be a huge issue.

Population control of some kind is so much easier now than if we wait 20 years and Chinese-like draconian measures become necessary.

1. http://www.newscientist.com/article/mg22329882.800-global-po...

Same article:

"These new predictions are drawing criticism. "Raftery's projections are too high for Africa, because they don't include the fact that female education is the key driver of fertility decline," says Wolfgang Lutz of the International Institute for Applied Systems Analysis in Laxenburg, Austria."