
Craigslist personals associated with 16 percent boost in HIV infections - smacktoward
http://arstechnica.com/science/2015/02/craigslist-personals-associated-with-16-percent-boost-in-hiv-infections/
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Animats
Related article: "Cheap Smartphone Dongle Diagnoses HIV And Syphilis In 15
Minutes".

There's startup potential there.

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httasdbaba
"Vertical integration."

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1337biz
Actually I like the critical causation and correlation discussion under that
subject. But I would like to propose that we are with any other suggested
social causality as critical as we are here.

It might seem convenient to use that argument when it comes to defending
something dear to us such as Craigslist. But when it comes to more sensitive
social and economic issues I wish we would see the same skepticism.

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lstyls
There is a gaping hole in this study which seems to be making the rounds on
the major news outlets: why did the authors not control for the arrival of
other personal dating sites?

I don't doubt the correlation but to pin this on craigslist specifically seems
dubious at best.

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smacktoward
They looked at Craigslist in terms of its rollout of local sites for the
various communities:

 _> Conveniently, the spread of Craigslist provides a natural experiment:
local sites were rolled out gradually over time, allowing the comparison of
infection rates before and after their arrival..._

 _> The data suggests that there was no rise in infection rate in advance of
Craigslist opening shop, and there appears to be a bit of lag after a local
site opens. This makes sense given that each city will take some time before
users discover and start using the service, and the authors looked into this
in more detail by tracking the number of ads present in each local site.
Within a year of the opening of a local Craigslist, as activity picked up, HIV
infections began to rise. The effect remained after the authors controlled for
a variety of other demographic factors in each area._

So if the data says you can consistently expect a spike in infection rates a
year after a local CL opens, and that effect is consistent across communities,
it seems unlikely that other sites would be affecting that -- unless they were
rolling out their own local sites in the same communities as CL was, at
roughly the same time.

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droidist2
16% boost in [new] HIV infections, or a 0.7% increase in HIV cases.

Of course the title makes it sound 23 times more severe.

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Demiurge
In related news: sex associated with 100% boost in sexually transmitted
diseases.

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hartator
This kind of article repulses me. Making the link between Craiglist and HIV
rate doesn't make sense, correlation is not causality.

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barry-cotter
You can never absolutely prove causality. But as is pointed out in the article
Craigslist became available in different cities at different times. The
pattern of a lag followed by an increase in STDs was found in many cities.

Whether one is repulsed by the implications of a study has no effects on its
truth value.

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tunesmith
Something else could have caused both the STD increase and the appearance of a
local craigslist presence. Like, say, a certain critical mass of population
density.

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ryan_j_naughton
Exactly. Craigslist isn't randomly opening their local sites. They are doing
so in response to changes in communities following some semi-strategic growth
strategy. Its not a natural experiment as claimed by the authors at all. Its
like looking at the effects of google fiber on the cities it launches in
without taking into account that those cities were selected by google for a
reason. Quasi-experimental methods would be helpful here like a propensity
score matching to match the cities to others that are like them and make
pseudo-controls.Even then you can't consider this remotely a natural
experiment.

