A new working paper released by the National Bureau of Economic Research suggested that the rise of the iPhone may have played a major role in the sharp decline in U.S. birth rates that began in 2007.
The paper, written by economists Caitlin K. Myers and Ezekiel Hooper, argued that smartphone access changed how Americans socialize, date, and spend their free time — ultimately contributing to fewer births, especially among women under 30. The researchers pointed to survey data linking smartphone access to fewer in-person interactions, lower sexual frequency, and higher pornography consumption.
“Taken together, these cohort effects imply that the diffusion of the iPhone deepened the decline in births among women under 30 while suppressing the rise in births among older women,” the paper states.
The paper draws on a natural experiment created by Apple’s exclusive deal with AT&T. When the iPhone launched in June 2007, it was available only on AT&T’s network until February 2011, giving researchers a way to compare areas with different levels of early iPhone access.
Myers and Hooper estimate that the iPhone’s introduction accounts for somewhere between 33% and 52% of the decline in the U.S. fertility rate among women ages 15 to 44 between 2007 and 2011.
They found that iPhone access reduced births by 4.5% to 8.0% among women ages 15 to 19 and by 3.2% to 6.6% among women ages 20 to 24. Smaller but statistically significant declines appeared in older age groups.
According to the authors, the U.S. general fertility rate has fallen by 22% since 2007, a sustained decline they argued cannot be fully explained by the common explanations such as the Great Recession, increased access to contraception, rising housing and childcare costs, and delayed marriage.
Provisional Centers for Disease Control data from 2025 also showed the U.S. fertility rate at a record low. The general fertility rate fell 1% from 2024 to 53.1 births per 1,000 women ages 15 to 44 and has generally declined by 23% since 2007.
Though the paper does not argue that smartphones are the only cause of declining fertility, the authors said the timing and persistence of the decline closely align with the rapid spread of smartphones in a way that suggests changes in digital behavior have likely reshaped Americans’ relationships.