Also, having a lot of children meant that when parents got old they would have plenty of children and grandchildren to take care of them. Then, there was a clear cost benefit to having lots of kids. Not so now. The answer, say demographers, lies in the threads of society. Links to grandparents are strengthened, ties are created between in-laws.
Siblings become aunts and uncles.
A couple's children connect them to other couples with children. It is especially important in low fertility populations such as the U.S., where 2.3 children is still the norm. People in the U.S. appear to believe that the economic sacrifices for children are unimportant when compared to the social benefits. Once more, they are not concerned about the impact of childbearing on their careers. They believe that parenthood is superior to childlessness.