It is the education of women that leads to a fall in Birth rate. It is counter productive in the long run though, if you look at where say japan is to where kenya is (for example) kenyas population could go on like that indefinatly, and has done in fact - Japan will simply die out.
It does not defy logic at all. In countries where the chances some of your children will die - you have a couple more to compensate - and then you have a couple more because your fella wants to show how fertile he is. In the 'developed' (ha) world, you know the chances are your child will survive, and you also know in order to survive you've got to make a living - so you have fewer kids and later. Nothing in that defys logic.
eugenics doesn't work because men are not meant to run that system. People are arrogant and people do not fully understand the implications of their actions, how humane you are has nothing to do with it and I never suggested it did. What we have at the moment, however, is probably just as absurd as Eugenics. People live too long and don't reproduce - that sounds like a dead end street to no where to me.
just to qualify all this a bit, I'm not just making it up as I go along, I have actually studied some of this stuff lol.