Since its founding, America has enjoyed population growth famously fueled by high immigration rates. But Americans have historically had large families compared to other countries, as well. But times are changing. Birth rates today have fallen to their lowest point in history. And while birth rates have historically been connected to economic cycles, the present decline is happening during good economic times. The causes of the decline will be familiar for many viewers, high housing costs, less dating and marriage, economic and social uncertainties. And even though surveys show Americans still want big families, there are no cheap, easy solutions to fix this problem. And unfortunately, the problem is self-reinforcing. Fewer children means that future generations will have fewer workers serving more people, who themselves will have less time to bear and care for children, or retirees for that matter. Even if Americans reform housing policy, or offer greater financial support for families, our birth rates will continue to decline, and the fast economic growth that made America so strong in the 20th century could vanish in the 21st.