A Sunday Times article asks the question of why there are so few babies born in parts of Europe. This is of course the same issue that Japan, Korea and some other countries are grappling with as well, and one that I've tried to cover before. The piece is rather verbose (yes, yes, I know - "pot, meet kettle. I'm sure you'll be god friends!") and light on detailed statistics, but it's a good read.
The piece describes how fertility has plummeted the world over, but fallen far below replacement in in southern and eastern Europe (the focus of the article) as well as in some parts of Asia, notably Japan and Korea. The reason is not the loss of religion or traditional values as some would argue; indeed, low-fertility southern and eastern Europe is a lot more conservative, family oriented and religious than the European north (which has a much healthier fertility rate).
And that is the key. In economically backwards, conservative, agrarian societies the fertility rate is high. A conservative, rigid lifestyle is well adapted to the economic situation - is perhaps necessary for social cohesion to be maintained.
In economically advanced, liberal societies with equal opportunities and help to combine children and an uncertain working life the fertility rate is, again, fairly high. The Scandinavian welfare state model provides assistance to parents with accessible daycare, paid parental leave, free schooling and so on. The US free-market model give parents enough workplace and societal flexibility to easily change occupation and working hours and allow people to leave and reenter the workforce without career stigma - the normally conservative USA has a notably liberal view of family life with regards to career and workplace issues, belying the idea that US moral conservatism is the reason for the fertility rate.
But the southern European countries along with Japan and Korea only modernised halfway. They are economically liberal, advanced societies that demand a great deal of flexibility and career committment from its citizens. But they still expect family life to conform to agrarian family values that are incompatible with their own societies; values that prevent them from providing the same support and flexibility to their citizens that the above societies do. They refuse to change their family and lifestyle values, and they can't renounce modernism and go back to a pre-industrial agrarian life. Stuck in the middle, prospective parents end up not having the children they wished they could have.
The greatest risk is being pointed to by Germany, as the article shows. There, being childless is increasingly seen not just as another lifestyle choice; it is gradually coming to be a desirable one. In most societies with a low fertility rate people want ot have more children than they do. But if people have fewer children than they want for long enough, that lower level will increasingly become the social norm. When people look around and see most of their peers and their parents generation with only one or no children, that becomes normal. If the societal tension between conservative family values and modernism persists for long enough - a couple of generations or more - then people may simply no longer want to have enough children even if they can.