Why has the US hit a record low fertility rate?

Fertility rates are declining around the world, and it's leading to dramatic generational and economic shifts.Plus, from babies to boomers. As the number of babies being born continues to fall, boomers are aging more gracefully than ever.This year, the post-World War II babies are turning 80 and they’re changing old age for themselves and future generations.We're looking at why the U.S. has hit a record low fertility rate on this hour of All Sides.Guests:Wendy Manning, co-director, Bowling Green State University's National Center for Family & Marriage ResearchMichael Kuhn, Vienna Institute of Demography at the Austrian Academy of SciencesLuke Yoquinto, science writer and research associate, MIT Age Lab