Can Smartphones Explain the Drop in U.S. Birth Rates?

A provocative new working paper suggests that the spread of smartphones — specifically the iPhone — could explain between 33% and 52% of the decline in U.S. birth rates since 2007. The study, by Middlebury College economist Caitlin K. Myers and her stepson Ezekiel Hooper, has ignited a fierce debate among economists, demographers, and technology critics about the role of digital devices in reshaping family planning.

The Puzzle of the Persistent Baby Bust

The U.S. general fertility rate has fallen by 22% since 2007, from approximately 2.12 births per woman to roughly 1.62. At first, economists assumed the Great Recession was to blame and that birth rates would rebound once the economy recovered. But they didn’t. “Whatever it is, it must be big, and it needs to coincide with about 2007 because that’s when we see all the births go down,” Myers told NPR.

That year also marked the introduction of the iPhone — a device that would fundamentally alter how people interact, date, and access information.

A Natural Experiment in Smartphone Access

The paper, titled “Is the iPhone Birth Control? Causal Evidence from AT&T’s 2007–2011 Carrier Monopoly,” leverages a unique natural experiment. From June 2007 through February 2011, the iPhone was sold exclusively on AT&T’s network. This created variation in access: counties with extensive AT&T mobile broadband coverage had early iPhone access, while those with limited coverage did not.

Using entropy-balanced Poisson and synthetic difference-in-differences methods, the researchers found that access to the iPhone reduced births by 4.5–8.0% among 15- to 19-year-olds and 3.2–6.6% among 20- to 24-year-olds. Smaller but statistically significant declines were observed among older cohorts. Placebo tests using Verizon and Sprint’s pre-2011 coverage footprints returned null results, strengthening the causal claim, according to the NBER working paper.

Three Mechanisms at Play

Myers and Hooper identify three primary pathways through which smartphones may suppress birth rates. First, screen time displaces in-person socializing. “The smartphone fundamentally changed the way adolescents spent their time outside of school,” Jean Twenge, a professor of psychology at San Diego State University, told NPR. “They started spending a lot more time online and on their phones and a lot less time hanging out with their friends in person.”

Second, increased access to pornography may serve as a substitute for in-person relationships. “When I talk to my students at Middlebury College, this is the first one they actually bring up,” Myers said. “Pornography was proving to be a substitute for in-person relationships.”

Third, smartphones put information about contraception and abortion at users’ fingertips, potentially reducing unintended pregnancies.

Methodological Skepticism

Not everyone is convinced. Elizabeth Nolan Brown, senior editor at Reason.com, published a pointed critique arguing that the study’s design suffers from confounding variables. “It becomes really unclear: Are we looking at iPhone effects, or just urban vs. rural fertility trends during the Great Recession?” she wrote in Reason.

Key concerns include the fact that high AT&T coverage areas were systematically more urban, where fertility was already declining faster for other reasons. The study also lacks individual-level data — it measured overall birth rates in areas with more or less AT&T coverage, not whether iPhone users specifically had fewer babies. And notably, the study found “no effect” for Black women of any age, a puzzling result that critics say hints at confounding socioeconomic factors.

What the Study Does and Doesn’t Say

Myers is careful to qualify her findings. “We’re not saying it’s all the iPhone,” she told CBS News. “What we are saying is that it is a really important factor to consider. Over this short period of time, it could explain about a third to a half of the decline. Now that leaves about half to two-thirds unexplained.”

Those other factors include the high cost of child care, women delaying childbearing, and broader global demographic trends that predate smartphones by decades. South Korea’s fertility rate dropped from 4.5 in 1971 to 1.5 by 1987 — a decline of three children per woman — long before the first iPhone.

Broader Implications

The debate extends beyond academic circles. The Trump administration has floated ideas such as a “baby bonus” for new parents and introduced a tax-deferred investment vehicle for children with federal contributions of up to $1,000. Yet even countries with far more generous parental programs, like Norway, have seen birth rates continue to decline.

The stakes are high. The Social Security Administration warned in June 2026 that the program risks exhausting its trust fund as soon as 2032, with fewer workers supporting more retirees. “It’s a real concern for economic growth to have a population with fertility below replacement levels,” Myers said.

What to Watch

Even if the smartphone effect is real, its interpretation remains contested. The negative narrative — that phones displace social interactions and increase loneliness — competes with a more positive one: that smartphones empower young people with information about contraception and expose them to alternative life paths, reducing unintended teen pregnancies. As economist Tyler Cowen noted on Marginal Revolution, “An interesting and difficult to discuss question is how much we actually want teen fertility rates to decline, and to what extent we should consider such declines a good thing.”

With smartphones now ubiquitous, the key question is whether birth rates will level off or continue to fall. Myers says only time will tell: “I think it’s possible that we’ll continue to see effects of phones on behavior and outcomes like fertility for years to come. But we’ll just have to keep watching.”