[FabHK]

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.

[hansonkd]

Not to be pedantic and I agree with what you are saying but:

> 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

This does not mean that just because they had those obvious questions that they were properly resolved. Human history has a long track record of people who knew better but chose to ignore. In science there is an incredible pressure to have positive results rather than negative ones (IE nobody would care or know about this study if the title was "we looked and iphone doesn't explain 33-52% of fertility decline"

[makeitdouble]

> natural experiment: It was only available in certain regions.

This study treats ATT doing market research and progressive rollout through prioritized markets as a "natural experiment".

We could at least agree it's specifically chosen population, whatever ATT marketing dept had in mind when they planned the rollout.

[tylervigen]

Right but the “certain regions” were affluent metro areas, the control group was rural counties, and the timeframe was the Great Recession.

Even the study authors acknowledge the severe risk of the huge confounding variable.

[virgilp]

That's for the good studies. Let's not pretend that all published studies are honest. Unfortunately it is quite reasonable to be skeptical about extraordinary claims such as this one.

[rayiner]

It's not reasonable when the skepticism is disproven by looking at page 11 of the paper that's in the link.

[FabHK]

It is reasonable to be skeptical, absolutely. But responding to a study like this with "haha what about if only rich people got iPhones" or "bro don't you know that correlation does not imply causation" is juvenile.

[virgilp]

To be fair, their control variables treat the first objection (wealth), not the second (brand preference; and yeah there's some correlation but one doesn't imply the other)