Both statements are meaningless. People either will or will not have more children (probably not, as all experience has shown that populations stabilize once the economy rises sufficiently far above the hand-to-mouth level).
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.