Blood Brain Barrier said:
Well there's the fact male sperm count decreased by 32% in France over the last two decades
http://www.bbc.co.uk/news/health-20593467
Yeah, the research was in France but I don't see any reason to think the same we wouldn't get the same result in any other 1st world country.
Of course, the researchers and medical professionals will see this as a 'health problem' but I see it as a blessing. We're overpopulated. As much as economists, governments and corporations like to think, infinite growth is not possible, at least without destroying ourselves in the process or compromising our life to the point it's not worth living.
Unfortunately this won't affect population levels due to artificial insemination unless fertility gets REALLY low. But I personally wouldn't want an adopted child especially if that kid was from the 1% of males in my country that could have kids. If that happens genetics will become hugely important - when half the people in your city will be from your own family tree that cuts down your choice of reproductive mate quite a bit.
I could even picture the emergence of the occupation of sperm donor as a well-paid full-time job and a new class of superstars alongside today's sportspersons and CEOs.
Most developed nations are either at or just barely above the replenishment rate (I don't remember what the 'official' name for that is, so whatever).
The overpopulation thing stems from places like Africa and Indonesia where there are people having 8-12 kids each. Third world countries have really high birth rates by default, basically. So the fact that people in France might be having less kids will have a very negligible effect on overpopulation as a whole.