Why are birth rates so high in poor countries?

Poor countries usually have no organized ways of caring for older people, so making sure that you have kids to look after you when you're old and weak becomes important. Poor countries also have a fairly low survival rate, so a family have to try for many babies to get some to survive into adulthood.

There may also be religious issues that don't allow for contraceptives, or religious instructions to raise big families.

Also in poor countries, people cannot afford contraception or do not have access to contraception.