The U.S. has joined the growing group of developed nations with declining birthrates. Some consider this a shift from the personal sacrifice of meeting traditional values to a focus on liberation, personal happiness and urban hip. Economics are also playing a part. Family income has stagnated in the last decade so more women are working to help the family maintain middle-class status. Children are a delight but they also require a lot of time and money, which families don't have a whole lot of to spare these days.