According to recent data from the U.S. Census Bureau, the average size of the American household has decreased by about one person. American culture is definitely voting for the smaller family and material wellbeing over the riches of multiple children. If any culture can materially afford big families, it is ours. Even from an economic point of view, the United States is powerful not because of its standard of living or its natural resources, but because of its greatest resource: people.
The medieval theologians and philosophers, in talking about God, say: Goodness diffuses itself, it wants to be shared by many. If our culture is so good, then why don’t we want to have more children and share it with them?