US fertility rates have dropped about 22% since 2007, coinciding with the rise of smartphone use, according to research analyzed by multiple sources including the National Bureau of Economic Research (NBER) and Middlebury College economists [1, 2, 3].

Middlebury College researchers studied differences in AT&T network coverage in US counties from 2007 to 2011 to isolate smartphone impact, finding iPhone proliferation linked to a 4.5% to 8.0% birth rate decline among females aged 15–19 and a 3.2% to 6.6% decline for those 20–24 [1, 2, 3, 4]. Smaller decreases occurred among older women as well [1, 4].

The researchers suggest smartphones led to less in-person social interaction and sexual activity, increasing consumption of digital content like pornography, which may substitute for partnered sex. Economist Caitlin Myers of Middlebury said smartphones are not the "only factor" but changed behavior patterns by reducing face-to-face contact and preventing intimate relationships that lead to childbearing [2, 5].

A separate May 2026 study by University of Cincinnati economists examined smartphone penetration and teenage fertility in 128 countries. It found a similar accelerated decline in birth rates following smartphone emergence even across countries with diverse healthcare, welfare, economic and cultural conditions. Nathan Hudson and Hernan Moscoso Boedo said the global trend shows a "common global technology shock" [4, 5]. Economist Phillip B. Levine called it "one more example of social influences leading to lower birth rates" [5].

However, some academics remain cautious. Skeptics note teenage birth rates in the US had been falling since the 1990s, before smartphones, and urge caution in attributing causality solely to technology [2, 6, 7]. Baruch College economist Theodore Joyce called the smartphone hypothesis "still speculative" [2]. The consensus is that economic factors, contraception use, female education, and housing costs all play roles but do not fully explain the birth rate decline [1, 3].

The US Centers for Disease Control (CDC) confirms birth rates remain at historic lows. Several Asian countries continue to face population challenges despite policy efforts to reverse declines [3, 6, 7]. However, the recent research has yet to address how governments might use these findings to counter low fertility rates [2, 8].

The initial Apple iPhone launched in June 2007 on AT&T’s network in the US, marking the start of this period [1, 4]. The Middlebury College study was published on June 8, 2026, by the NBER [1]. The University of Cincinnati’s global analysis came out in May 2026 [4].