It has nothing to do with money. That's the easy cop out. My parents struggled every single day raising 6. Dirt poor societies all over the world have large families.
The reasons are simple - the birth control pill, abortion on demand, women getting married later in life, more wealth (not less) and more opportunity for the majority to do things and go places only the rich could do 30+ years ago.
Dirt poor societies all over the world have large families.
They have large families in order to insure their economic well-being when they get too old to work. Also, a lot of those kids in dirt poor societies tend to die.