Researchers used AT&T’s early iPhone monopoly to investigate whether smartphones changed social behaviour enough to reduce births

When I first read the headline, I thought it was a joke. Then, when I looked more carefully, I realised it was an actual research finding, published this June by the National Bureau of Economic Research.

Did the iPhone lower the birth rate in America?

The researchers are Caitlin K. Myers and Ezekiel Hooper. Their approach is careful. Rather than speculating about smartphones and social behaviour in general, they found a natural experiment embedded in the iPhone’s launch history. From 2007 to 2011, AT&T was the only carrier that sold iPhones in the United States. This meant that counties with strong AT&T mobile broadband coverage received early access, while counties without it did not. The researchers compared birth-rate trends between those two groups across the same period.

The finding is striking.

They estimate that access to the iPhone reduced birth rates among teenagers by 4.5% to 8% and among adults in their early twenties by 3.2% to 6.6%. Across the broader population, their model suggests the iPhone’s diffusion may account for roughly one-third to one-half of the overall decline in the US general fertility rate between 2007 and 2011.

To be fair about what this paper is and is not: it is a working paper, not yet peer-reviewed.

The researchers are careful to say they have identified a strong correlation through a well-constructed natural experiment, and that the evidence is consistent with causation, but the mechanisms remain indirect. They ran robustness checks using Verizon and Sprint coverage data, neither of which showed comparable effects before those carriers gained access to iPhones, strengthening their argument. But the final causal verdict belongs to future research.

What the paper proposes, and what I find worth sitting with, is not that the iPhone is contraception. The argument is subtler. The iPhone appears to have reshaped how young people spend time together. More hours alone or online. Less face-to-face socialising. Declining sexual activity, which national surveys independently confirm, was already falling among young adults. Greater access to digital entertainment as a substitute for in-person relationships. And separately, easier access to information about reproductive choices. None of these individually is a bombshell. Collectively, and tied to a specific, measurable event like the iPhone’s arrival, the picture becomes harder to dismiss.

I have been thinking about this from a different angle.

We often discuss technology’s impact on work, on decision-making, and on how organisations run. We talk less about how deeply technology reshapes the texture of private life, the kind of socialising people do, and the pace and nature of their relationships. The fertility finding, if it holds up under further scrutiny, is one of the most concrete empirical signals we have that a single technology product reshaped private human behaviour at scale within just a few years of its introduction.

That has implications far beyond demography. For anyone advising companies on how they introduce technology to their people, or thinking about what sustained digital saturation does to the human beings inside an organisation, this research is worth reading carefully.

The paper is available on the NBER website. The full citation is Myers, Caitlin K. and Hooper, Ezekiel, published June 2026.