The world’s population is set to reach seven billion on Monday, October 31, 2011. And all this week, The Takeaway is talking about what this monumental number means for people, resources and the planet. Statistics in the U.S. show that the average American woman has 2.1 children. With these numbers the population balance should looks good for the U.S. But a new book shows that this is not the case. Sharon Lerner is the author of “The War on Moms: On Life in a Family Unfriendly Nation” and senior fellow at Demos. She talks about the increasing fertility class divide in America.