Why are so many large countries shrinking fast?  Fertility rates below replacement are so endemic in Europe that its countries will do well to still exist in a couple of centuries; at least with the same peoples, culture and values they do now. 
An opinion piece in the Huffington Post this week discusses one cause of such low fertility.  Its sub-title reads:

“We are functioning in a society that pretends women don't grow up to become mothers.”   There is no way to know what being a mother is truly like until you are one.  I certainly had no idea.  However, expectations of life, pre-set goals, the way you’ve been encouraged to shape your identity over the many years that come before, and the value placed on motherhood by the society around you all go a long way to affecting how well you cope with the job.  Samantha Johnson writes:

In the fight to ensure equality, as we preach to girls that they can -- and should -- do anything a boy can do, we are failing to prepare women for one of the greatest challenges so many of them will face; motherhood. We are teaching our young people that there is no value in motherhood and that homemaking is an outdated, misogynistic concept. We do this through the promotion of professional progression as a marker of success, while completely devaluing the contribution of parents in the home.

We then wonder why, when these girls become women who turn into mothers, they suffer from depression, anxiety and struggle to find a sense of self or identity. Are we truly helping women get ahead, or are we instead setting them up for a future of self doubt and a sense of failure? You can read the whole opinion piece for yourself.   My experience of education is certainly that teachers are so conscious of pushing girls to new heights of achievement in the world that the reality of growing up to become a mother and run a family alongside these things is barely mentioned.  Women who are either unprepared for motherhood, or find it difficult to envisage how it will fit with the life they have so far aspired to, is certainly one cause of low fertility around the world.