Are you ready for this?

[Kaz]

The greatest form of birth control and population stability is prosperity. ...

Absolutely. The higher on the hog people get the more on average they seem to naturally slow down in reproduction. I've never studied that phenomenon in depth but it appears to me that it is a simple resources distribution situation. It simply takes more money per child the more affluent the parents are. I guess an additional factor would be that having more resources can lead to more options in life, so parents might want to have their one or two kids then get back to all their hobbies, travelling, etc., whereas poorer parents pretty much work just to live. Interesting stuff. The optimist in me is still holding out for that prefect scenario: so many of us become so prosperous so fast we level off in population. Win win I wouldn't put money on it though.