In Germany it's sophistication, lack of lebenraum. In America it's taxation, sophistication, couples forced into the labor market, Hillary Rosie and Barbara, family planning kooks et am neuseum.
In Afganistan it's Islam, dominate men, polygomy and unsophistication. In Russia a dooms day complex caused by 70 yrs of communism, lack of justice and opportunity, atheism. In China it's compulsary abortion and sterilization.
All this is caused by those in power over our institutions and government, and it can be changed! Pat is right again in bringing up this important subject.
You can't write it off with psycholbabble.
In fact, every nation on this planet with a high per capita income (other than one associated with extracting oil from the ground), has a low birth rate, and most with middle of the road per capita incomes are joining the club. The correlation between per capita income levels and birth rates is very, very high. With respect to most other factors, it is very, very low.