Did the iPhone Cause the Baby Bust? Two Studies Make the Case

Two new academic studies are the first to rigorously test whether the smartphone caused the global fertility decline — and both find compelling evidence that it did. The timing has long been suspicious: U.S. birthrates began falling in 2007, the exact year Apple introduced the iPhone. Until now, that correlation had no rigorous causal proof behind it.

The more striking of the two papers comes from Caitlin Myers, an economist at Middlebury College, and her student Ezekiel Hooper. They exploited a natural experiment: the original iPhone launched exclusively on AT&T's network in June 2007 and stayed that way until February 2011, meaning some U.S. counties had near-universal early smartphone access while others had almost none. Comparing fertility rates across those counties, their National Bureau of Economic Research paper estimates the iPhone caused as much as half of the fertility decline between 2007 and 2011. The effect was sharpest among 15-to-24-year-olds. Possible mechanisms include reduced in-person socializing (and thus less sex), easier access to pornography substituting for physical intimacy, or better access to contraception and abortion information.

The second study, by University of Cincinnati economist Hernan Moscoso Boedo and Ph.D. student Nathan Hudson, takes a global lens. Analyzing World Bank data on smartphone penetration and teenage fertility across 128 countries — including Iran, Costa Rica, Guatemala, Chile, Mexico, and Turkey — they found that teenage fertility declines consistently accelerated once smartphones became mass-market. They also tested U.S. data using broadband and 4G rollout geography, finding that counties with faster high-speed internet access saw steeper teenage fertility drops.

Not everyone is convinced. Wellesley economist Phillip Levine praised the Middlebury methodology but warned against reading the results too literally — AT&T's early network may have skewed toward wealthier or denser counties, potentially tainting the randomness the study relies on. Baruch College economist Theodore Joyce is more skeptical still, noting that teenage births have been falling since the 1990s, well before smartphones existed, and calling the smartphone hypothesis 'speculative.' The fertility puzzle remains genuinely hard: the Great Recession, rising female education, and shifting attitudes toward parenthood are all competing explanations, and isolating any single cause is enormously difficult.