Of course, many factors are at work when it comes to a lower birthrate: delayed marriage, the advent of contraception, education and career options for women, economic stability, and so forth. It's not yet clear how much of a deterrent exorbitant and widespread student debt poses to family formation, because the phenomenon is relatively new.
"There are not a lot of hard numbers yet," says Tamika Butler, director of the California office of the Young Invincibles, a youth advocacy group that has focused on the student debt issue since 2009, conducting studies and making policy recommendations to Washington. A 2012 Rutgers University study, "Chasing the American Dream: Recent College Graduates and the Great Recession," shows that 4 in 10 graduates from a four-year college program said debt has delayed major decisions such as buying a house or starting a family. And there is plenty of anecdotal evidence that student debt is delaying childbearing.