Live data from Hacker News

The iPhone explains 33–52% of fertility decline among women aged 15–44

nber.org

11–20 of 66 posts

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#11

So... Let me get this straight. Because people who had iPhones during the AT&T exclusive period has less kids... They think there is no other possibly explanation besides the iPhone, because they looked at similar groups on different networks and in different areas that didn't yet have coverage for iPhones? It definitely couldn't have been due to richer people having iPhones and having less kids, or people preferring…

[deleted]

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#12
"The fertility drop is concentrated among young populations and largely operates through declines in unintended births (Buckles et al., 2025), suggesting the operative margin may be less about the cost of raising a child and more about whether the relationships and sexual activity that produce children are forming at all."

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#13

So... Let me get this straight. Because people who had iPhones during the AT&T exclusive period has less kids... They think there is no other possibly explanation besides the iPhone, because they looked at similar groups on different networks and in different areas that didn't yet have coverage for iPhones? It definitely couldn't have been due to richer people having iPhones and having less kids, or people preferring…

Not every rich person got an iPhone. The rich people without an iPhone did not had equal amount of less kids. There are two groups, one has an iPhone, the other has not. The assumption is that two groups are big enough to have equal amount of people from any other group that can explain the decline in fertility, i.e. equal amount of rich/poor, educated, etc. They can control for this because they know which people had access to the iphone based on the AT&T network coverage.

At the end of the abstract they state the likely explanation of this seemingly spurious correlation: > National-survey evidence on time use and sexual behavior is consistent with the iPhone reducing in-person interactions, increasing pornography use, and reducing sexual frequency.

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#15

[flagged]

Every person after taking just one 101 statistics course tells everyone "correlation doesn't equal causation". But here, in the abstract is clear:

> National-survey evidence on time use and sexual behavior is consistent with the iPhone reducing in-person interactions, increasing pornography use, and reducing sexual frequency.

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#16

So... Let me get this straight. Because people who had iPhones during the AT&T exclusive period has less kids... They think there is no other possibly explanation besides the iPhone, because they looked at similar groups on different networks and in different areas that didn't yet have coverage for iPhones? It definitely couldn't have been due to richer people having iPhones and having less kids, or people preferring…

I suggest you read the abstract, at least. The fact that only AT&T had the iPhone back then resulted in a natural experiment: It was only available in certain regions. You can thus compare regions where it was available and where it wasn't, while controlling for "richer people" or "people preferring iPhones".

As a rule of thumb, if you look at something for 3 minutes and have some obvious questions, the scientists that looked at it for several years of their life in great detail might have had those same obvious questions as well.

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#17

So... Let me get this straight. Because people who had iPhones during the AT&T exclusive period has less kids... They think there is no other possibly explanation besides the iPhone, because they looked at similar groups on different networks and in different areas that didn't yet have coverage for iPhones? It definitely couldn't have been due to richer people having iPhones and having less kids, or people preferring…

Because correlation is not causation. If A and B correlate there's 3 options:

1) A causes B

2) B causes A

3) C causes both B and A (in some order)

4) your correlation figure is bullshit (hence not counted in the 3 options, but certainly with news these days, it must be mentioned)

A famous way to illustrate where this goes wrong is to show a map which libraries that loaned out Harry Potter books, and a map of where poodles got raped. Very high correlation, and obviously an example of the 3rd option.

(obviously both were caused by population density, which leads to both library creation and poodle-related crimes. And probably non-poodle-related crimes)

Re: The iPhone explains 33–52% of fertility decline among women aged 15–44

#18
post #5

I'll bite. Maybe it's not the iPhone itself, but social media. I have seen studies about damages that social media can cause in behaviours. This might be one of them. Smartphones are the catalyst to social media consumption as we know. Like people contantly on their phones everywhere instead of interacting with other people, for example.

Why not go further? It's the Internet as a whole. People socialising online, and online becoming an actual place people spend their entire lives within, free from the hard constraints of the real world, was the natural evolution of the Internet.

Plenty has been written about how any technological innovation leads to massive societal changes no one could foresee, and no one could avoid, but only analyze in retrospect.

Post reply on HN