
DUI rates decline in Uber cities - jmduke
http://blog.uber.com/DUIratesdecline
======
TrainedMonkey
If this is true, this is a big deal. However study is inherently flawed
because it uses only two cities for it's data. There are a number of factors
that could have called this result to be observed, for example increase in
SF's DUI due to more rigorous police patrols. I also did not see any seasonal
controls. DUI rates might be different depending on the time of year.

Here is what would provide for a way stronger claim:

1\. Aggregate DUI levels change since UBER started operating across all cities
with no UBER service.

2\. Aggregate same data for cities with UBER.

If UBER causes decline in DUI rates hypothesis is true, we can expect two
trends:

1\. On average cities with UBER will observe relative number of DUI's going
down when compared to cities without UBER.

2\. Amount of UBER rides given will be positively correlated with decrease of
DUI rates.

Personally I think it would make sense that UBER decreased amount of DUIs and
I would really like a data released that can prove it.

~~~
opendais
It is probably true. Cheaper taxi services would cause ppl who drove drunk for
financial reasons to hire an uber car.

Tbh, I am surprised no city ties liquor licenses to taxi services. (E.g. sell
an open container, have a contract with a taxi company to drive people home)

~~~
trhway
>Cheaper taxi services

don't know about cheaper. "Reliable" would do the trick for me. Remember
waiting for a taxi for an hour for a 5 mi ride. I'd walk it easy if i knew
that it'd take an hour to wait.

~~~
InclinedPlane
Reliable, convenient, timely, and available anywhere. Those are all pretty
significant since bars are not always in downtown cores, and taxis rarely
patrol around house parties.

------
pumblechook
Honest question: is this not a classic example of the fallacy of claiming
causation in an observational study, in the presence of a potentially infinite
number of confounding variables? I'm not a statistics expert by any means, but
this is one of the first things taught in an intro stats class: observational
studies can establish relationships (correlation), but only well designed
experiments can establish causation. This is quite obviously an observational
study, and a tiny one at that.

Furthermore, wouldn't the fact that marijuana was legalized in Washington
violate the parallel trend assumption that has to hold to use difference in
differences when comparing with San Francisco?

I understand the powerful incentive for Uber to provide this narrative, and I
think anything that encourages people to not drive while intoxicated is a good
thing. I just find it disheartening that companies feel the need to start with
these powerful marketing narratives (which these types of 'studies' really
are, not honest efforts to uncover useful knowledge), and use dubious analysis
to give those narratives credibility.

It's not that I'm disputing there is a relationship - they've obviously
identified that. I have a problem with statements like these: "We estimate
that the entrance of Uber in Seattle caused the number of arrests for DUI to
decrease by more than 10%." And, "We can reasonably extrapolate these results
and apply them to what we consistently hear from our riders in Chicago and
elsewhere." It is quite a stretch to claim that Uber _caused_ anything based
on an observational study with a minuscule amount of data, and it is even
further of a stretch to claim that you can combine this claim with _anecdotal_
evidence and somehow generalize it into principle.

------
kiyoto
The author probably has no background in experimental design, so I would spare
him of statistical scrutiny. This includes the author's furtive attempt to
sneak in causation into a simple regression.

Or, if I were to give the author of the benefit of the doubt, Uber realized
that this potentially inaccurate statistical claim ("Uber is inducing a drop
in DUI") can help them win people's goodwill in areas where their operations
have been thwarted/stunted by bureaucracy.

If so, they are really shrewd (for most laypeople don't understand anything
about statistical inference), but I am not sure if I would trust a company
that resorts to such a disingenuous campaign.

I actually want Uber to be a success. I love their service and envision it to
be a real-time bidding platform for all sorts of (offline) services. But at
the same time, I would be concerned if a company of such great promise is
already acting intellectually dishonestly.

Hence, I really, really hope the author is just an idiot.

~~~
leorocky
> Hence, I really, really hope the author is just an idiot.

Not knowing good experimental design doesn't make someone an idiot.

~~~
kiyoto
I agree. Not knowing anything does not make anyone an idiot. Not realizing
that you do not know something, however, kind of does.

~~~
leorocky
If "unknown unknowns"[1] make people idiots then everyone is an idiot and the
term is neither an insult nor meaningful. Likely there's some other reason you
have for wanting to use a mean and angry word that you haven't articulated
well. What you describe in your original comment is probably just the
Dunning–Kruger[2] effect.

[1]
[https://en.wikipedia.org/wiki/There_are_known_knowns](https://en.wikipedia.org/wiki/There_are_known_knowns)
[2]
[https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect](https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect)

~~~
kiyoto
It might be a case of the Dunning-Kruger effect. Either way, I am willing to
concede that I misused the term (perhaps I am the one being an idiot here). I
am still surprised that the blog post got published on Uber's blog though.

------
lifeformed
Oh god, that chart [1] took me a long time to understand. Since when was it a
good idea to use floating, negative bars in a bar chart to indicate change
over time.

[1]
[https://lh6.googleusercontent.com/3VC2E1ok_hRV5MPXS3J9s5u9xe...](https://lh6.googleusercontent.com/3VC2E1ok_hRV5MPXS3J9s5u9xeF_rMXI8frdl-
KlLbG_87w_nmlgW0Ary0nBMHcRUwNC6tbqxkb9-5FeeE6W8wNApC28XgP-
Oprr3KyZCXLcL2rzbqQVK_SrCQTkQyMsWQ)

~~~
iamshs
I think that is a waterfall chart, badly drawn. The gain bars are typically
shown in green, and loss in red.

------
AlwaysBCoding
This is a pretty big deal. As short-sighted and destined to fail as the
current backlash against Uber is (see the cease-and-desist order issued in
Virginia this week), it becomes a different narrative altogether if you can
show that Uber saves lives. Any correlation with a decrease in DUI's is going
to be hard momentum to counteract. If Uber can show definitively that highway
safety increases in Uber cities, it's very compelling evidence that they
should be in every major city regardless of existing taxi laws.

Although lobbying for increased highway safety has gotten us some atrocious
national policy in the past (the 21 drinking age) - it would be nice to see it
be used for a good cause here and give more cities modern transportation
options.

~~~
tzs
> If Uber can show definitively that highway safety increases in Uber cities,
> it's very compelling evidence that they should be in every major city
> regardless of existing taxi laws.

No, it's evidence that cities should increase the availability of taxis or
taxi-like services in general, not Uber specifically. In fact, due to more
stable pricing, I'd expect Lyft to do better than Uber, and normal taxis to do
even better.

~~~
kelnos
Why would normal taxis do better? (Currently in SF) they're more expensive,
the cars are less-well-maintained, and the drivers are often... I won't say
"rude", but... less than pleasant to deal with. Not to mention the dirty looks
you get when you want to use a credit card, and just the hassle of payment and
tipping. Their dispatch services suck (they say 20 minutes and most of the
time never show up), and hailing a taxi is a pain.

Simply increasing the availability of taxis won't fix those problems.

~~~
opendais
If operating a taxi was $250k cheaper (the price of a medallion in SF) you get
Uber's results.

Most of uber's "advantages" stem from the fact taxi medallions get leased for
about $1k/month that uber's contracted drivers don't pay.

~~~
dnautics
And not exploiting their drivers, and having a gay-friendly employment force,
and having rated drivers, and having trip itinerary transparency, and not
having to cruise as much, an having visibility over where other drivers are to
improve coverage...

~~~
silencio
Some of that is good and true, but trip itinerary transparency and rated
drivers don't necessarily make for a good ride...

4 of 5 of my Uber rides in the last two weeks had 4.8-4.9 star drivers that
didn't know the intersection I wanted to go to in SF. They all searched
directions to/from: Sutter/Stockton, 20th/Valencia, a block from
Market/Church, and 4th/Howard - all of those being non-trivial streets in one
form or another ( _especially_ Market St, really, you're asking me for
directions to Market St, that's like asking me where the Strip is in Vegas).
Not to mention I'm not sure why they keep asking for directions too, since
it's not like a cab I'll never see again overcharging me through my own fault
- if I have a problem I will contact Uber and they will fix it (also a good
thing!). One guy even asked for instructions, disregarded them, got stuck in
traffic without ending the ride early, and made me and my husband late for an
appointment that we would have been 5-10m early for if he didn't space out -
helloooo 1 star rating. Oh, and half the time, I will get drivers with so much
cologne on that I feel sick.

Say what you will about the terrible state of cabs in SF because it's all true
and then some, but I think both cabs and Uber have a lot of _different_
problems to work out. A 5 star driver is not someone who has to enter in
"Market and Church" in a GPS, it's not someone that poured half a bottle of
cologne on themselves that morning, and it's most definitely not a person that
fucks around driving in the direction they were explicitly told not to go in.

Some days I am jealous of NYC and London and other cities where I've had
excellent experiences with cabs and Uber just adds a small layer of
luxury/convenience on top of that if I choose. SF used to be that way with
Uber a few years ago but not so much anymore - the price decrease and choices
are nice but I wish I could get quality too - both Uber Black and UberX are
just meh now.

~~~
dnautics
The rating inflation could be lyft's fault. The lyft system is specifically
inflated: 1 & 2 are really bad rides, 3 is "bad enough that you never want to
be matched up again", 4 is "needs work" and 5 is "good". If you have an
excellent ride, it's 5 + tip. However, deactivation is ALSO inflated, Lyft
wants only 4.5 + drivers (after a certain number of rides). Passengers
crossing between Lyft and Uber could be skewing the statistics of driver
ratings.

As a lyft (and uber, from time to time) driver with 9 years of living
experience in San Diego, there are times when I know exactly where the
destination is but I am not sure of the "best" way to get there, or I am
worried that there are multiple ways to get there and having the GPS decide
gives it an "objectivity" that CYA's me for 'dispute resolution' purposes.

And both lyft and uber have been expanding like crazy recently, so having a
4.8 or 4.9 could be the law of averages in small numbers working against your
experience.

------
anigbrowl
This is interesting, but it would be more compelling if it mentioned the time
scales involved. I really don't know if we're looking at 6 months' worth of
data, several years' worth, or what. I'm assuming it's corrected for seasonal
fluctuations, but with no longitudinal scale it feels a little handwavey.

~~~
freehunter
I would like to see a line graph, not some really weird bar graph (I've never
seen a graph like that, so it's unfamiliar and hard to read). Show me the
trend, preferably with different lines for marijuana in order to show it's
impact separately.

------
datawander
I don't really buy it. What if DUI rates fell across all cities nationwide,
regardless of Uber being on the market?

~~~
AlwaysBCoding
Doesn't really matter for winning the narrative.

The US enacted a 21-year old drinking age in 1984. It has been an absolute
train wreck. One of the most backwards and out of touch with reality national
policies that we have. The only reason it's still around is because of an idea
that it somehow "saves lives". The stat most often cited to "prove" this, is
the number of alcohol related traffic fatalities that have occured in the US
since 1984. They have declined, significantly. Does it matter that this has
nothing to do with the drinking age? Does it matter that number of highway
deaths have declined across the entire world, and at a much faster rate than
the United States? Does it matter that highway deaths declined at the same
time as a rapid increase in seat belt usage? No. None of it matters. In terms
of the narrative MADD won, and half the country believes the drinking age
saves lives, even though it's utter baloney.

If Uber can play up the idea that having Uber around saves lives, it's a trump
card. It doesn't matter how sound the statistics are, they'll win the
narrative in every city. As a politician do you really want to be against
saving lives?

~~~
Houshalter
It does do some good.

Countries with lower drinking ages have much higher rates of binge drinking.

The WHO Europe region has a 70% higher incidence of teen (15-19) binge
drinking than the Americas region:
[http://i.imgur.com/oAbeg7x.png?1](http://i.imgur.com/oAbeg7x.png?1)

Canada, with its 18 and 19 year old drinking laws has a far higher rate of
teen binge drinking than the US, as do the European countries:
[http://i.imgur.com/iaJbDLd.png?1](http://i.imgur.com/iaJbDLd.png?1)

Finally, we find that the US has a overall rate of binge drinking in the
middle of Europe, lower than France and the UK but higher than Germany and
Spain: [http://i.imgur.com/h0BkKGe.png?1](http://i.imgur.com/h0BkKGe.png?1)

~~~
venomsnake
You also have to give the value of 20-something binge drinking in both
continents for the picture to be complete. Us could have a perfectly good case
of postponed binged drinking.

~~~
Houshalter
This is possible although I don't have that data. It's still preferable as the
amount of brain damage would be significantly less than during teen years, and
they would hopefully be at least somewhat more responsible.

------
svsaraf
I'm having trouble understanding their statistical work. How is the
"differences in differences" framework different from having two experimental
groups and no control?

I'm also not sure that extrapolating to Chicago makes sense. I live there.
Since anecdotal observations seem to matter, it seems that the people who
would order an Uber car would call a cab if Uber wasn't available. It's hard
for me to imagine Uber providing such an addition in service that it would
change DUI rates.

------
md2be
Hello Uber, a better study would be the number of ER visits cuases by
suspected drunk driving. Hire me. There are data scientists and there are
creative data scientists.

~~~
andrewsturges
Uber can't hire you if they can't email you. So put one in your profile. :)

------
md2be
Bugs me when an analysis doesn't start with a visual inspection of the data.
How about a plot of DUIs vs Time? is it linear? Next does it show a
discontinuity at some pint in time? what effect does changing the bin size
(time) have?

------
hop
Uber has definitely cut down on the drinking and driving of my friends, no
question.

------
UVB-76
Hypothetical plot twist: The actual number of people driving under the
influence has not declined, but as police resources are diverted to Uber-
related incidents — e.g. drivers (allegedly) assaulting [1] or kidnapping [2]
passengers, or the generic disputes you would expect to arise from a taxi
service — their capacity to arrest people for DUI has declined.

[1] [http://www.latimes.com/local/lanow/la-me-ln-uber-driver-
arre...](http://www.latimes.com/local/lanow/la-me-ln-uber-driver-arrested-san-
francisco-20140604-story.html)

[2] [http://www.hollywoodreporter.com/news/la-uber-driver-
arreste...](http://www.hollywoodreporter.com/news/la-uber-driver-arrested-
kidnapping-709327)

------
marknutter
Uber should give people 10% discounts if their blood-alcohol level is above
the legal limit.

~~~
jerf
You might want to consider _all_ the incentives you'd be creating there....

~~~
mertd
Hey, Uber is buying the last round :)

------
sprw121
The results don't even looks statistically significant at the 5% alpha level.

~~~
IanCal
I'm not really following the analysis too well (I'd like to just see the raw
data) but when they did their differences in differences seattleTRUE:uberTRUE
had a p-value of over 0.05

------
justizin
I, too, will comment on this article without reading it!

~~~
datawander
Yes, I read the article and I applied an idea I took from one of the first
articles on Nate Silver's 538 'news' site [0] of using Bayesian statistics to
decode news as you read it and in my opinion the data presented is very
underwhelming and there isn't any firm ground they are standing on here.

Here's my 'Bayesian logic' applied to it. My 'prior believe' in the claim
being made is that I don't believe Uber has broad penetration across all
demographics. Yes, people who are in the tech world and under 30 know of them,
but not much outside of that. I was the first one of all my friends to use
Uber (I would know because I have gotten over $60 in credits for signing them
up). So outside of SF, my initial personal belief is that Uber doesn't have
wide usage. So either the largest demographic of DUI violators are nerds who
are younger than 30 or Uber is magically being used by people who would prefer
using a more expensive Uber service than driver over a cheap taxi ride.

So let's look at the evidence they provide to see if it changes my prior
significantly: one city was explicitly given data about without any hint as to
what time-frame they are talking about. The other cities were literally the
equivalent of hearsay arguments so because I'm the judge of this court, that
evidence doesn't count. When you're talking about month-over-month and even
year-over-year trends, a drop of 10% is just as easily explained by a random
process modeled as a poisson [1] over the entrance of Uber. I would know
having dealt with lots of time series data.

One finally comment, my apologies to the author of the bar chart, but that is
just terrible. It's hard to read and doesn't make much sense from looking at
it first. How many bar-chart graphs are out there that look like that? It
could just be me speaking aesthetically because I'm weirded out by the random
floating bars in the middle, but I feel Edward Tufte would have something to
say about that.

jusitizin, I know you weren't speaking to me directly, but I read the article.
Hope this comment proves it :)

[0]

[http://fivethirtyeight.com/features/a-formula-for-
decoding-h...](http://fivethirtyeight.com/features/a-formula-for-decoding-
health-news/)

[1]

[http://www.wired.com/2012/12/what-does-randomness-look-
like/](http://www.wired.com/2012/12/what-does-randomness-look-like/)

------
hayksaakian
This has about as much weight as pirates and global warming

[http://www.forbes.com/sites/erikaandersen/2012/03/23/true-
fa...](http://www.forbes.com/sites/erikaandersen/2012/03/23/true-fact-the-
lack-of-pirates-is-causing-global-warming/)

~~~
jdminhbg
No, it has more weight because there is a plausible mechanism for causation.
It isn't proof, but it's an interesting potential theory.

