Do Juvenile Curfews Increase Crime?

by on December 30, 2015 at 7:25 am in Data Source, Economics | Permalink

Washington, DC has a juvenile curfew law. Anyone “under the age of 17 cannot remain in or on a street, park or other outdoor public place, in a vehicle or on the premises of any establishment within the District of Columbia during curfew hours.” (There are exemptions for juveniles accompanied by a parent and for travel for jobs (no detours allowed.))

Curfew laws keep some juveniles off the streets during curfew hours but which ones? The criminals seem the least likely to be deterred and with fewer people on the street perhaps the criminals are emboldened.

The DC curfew switches from midnight to 11 pm on Sept 1 of every year. In a working paper, Jennifer L. Doleac and Jillian Carr test the effect of DCs juvenile curfew on gun violence by looking at the number of gunshots heard in the 11pm to midnight “switching hour” just before and just after Sept 1. From a summary:

…the September 1 change provides a clean natural experiment. If curfews reduce gun violence, then when the curfew shifts to 11:00 p.m. rather than midnight, gunfire between 11:00 p.m. and midnight should go down. Does it?

Just the opposite. Using data on gunfire incidents from ShotSpotter (acoustic gunshot sensors that cover the most violent neighborhoods in D.C.), we find that after the curfew switches from midnight to 11:00 p.m., the number of gunshot incidents increases by 150 percent during the 11:00 p.m. hour. This amounts to 7 additional gunfire incidents city-wide per week, during that hour alone. Jane Jacobs was right: the deterrent effect of having lots of people out on the streets is powerful. This makes juvenile curfew policies counter-productive.

The use of ShotSpotter data is innovative and avoids some problems with issues of police enforcement. Calls to 911, however, don’t show the same pattern as the ShotSpotter data which is worrying.

I’d also like to see more information on the proposed mechanism. Is it really the case that significantly fewer people are out on the streets at say 11:30 pm after the curfew has been lowered to 11pm than when the curfew was set at midnight? The curfew only directly affects people under 17 and, as noted above, there are quite a few exemptions. Also what are the ages of those typically arrested on the basis of ShotSpotter alerts?

By the way, on a typical day in DC there are almost 15 gunfire incidents heard by ShotSpotter (data here, the authors report 8 but that may be from a restricted sample). A lot of gunfire is heard around a handful of schools. The ShotSpotter system is quite accurate. Although it misses some shots it distinguishes shots from car backfires better than people do. I also found this note from the Washington Post amusing in a frightening way:

About a third of detected gunshot incidents in the city happen on New Year’s Eve or around July 4. Officials explain the high rate as celebratory gunfire.

1 Nodnarb the Nasty December 30, 2015 at 7:39 am

I think this can best be understood in tandem with a centralized versus dispersed view of the issue…

2 weareastrangemonkey December 30, 2015 at 7:59 am

Alternative mechanism: Teenagers go home earlier and they are more likely to update shotspotter.

This mechanism is very compatible with no increase in reports to the police.

3 A Definite Beta Guy December 30, 2015 at 9:42 am

I thought shotspotter was based on acoustic sensors, not neighborhood reporting?

4 A New Commenter December 30, 2015 at 8:12 am

How many of the shooters or shooting victims fall in the under 17 category? Is curfew designed to address shootings or other things such as vandalism or truancy?

Curfew is changing around the time that school is starting. Does the start of the school year lead to more shooting with people interacting with people that they would not otherwise interact with?

Baltimore, which is not far away from DC, does not have a curfew. Do the shootings go up more or less than the go up in Baltimore during the same period? There is an article from 2014 saying that Baltimore was getting ShotSpotter.

I was wondering if ShotSpotter can tell the difference between gunshots and fireworks, and it appears that it can.

5 C December 30, 2015 at 9:17 am
6 prior_test December 30, 2015 at 9:46 am

‘Is curfew designed to address shootings’

You noticed that too, it seems. Almost as if someone decided that gunshots, probably from weapons not being used by 13 year olds, are the best way to measure the effectiveness of laws designed to help other goals. In part by trying to use a legal framework to make up for a lack of effective parenting. The amusing thing being, of course, that drinking laws concerning under 18 year olds tend to be strictly enforced, and no seems concerned about the number of gunshots coming from the area around bars when they are open as compared to when they are closed as showing that strict alcohol licensing laws are contraproductive to reducing crime by increasing the number of drunk owners of weapons.

What would be even more amusing is to see if the number of gunshots in DC has increased or decreased since District of Columbia v. Heller, and what that would mean in terms of contraproductive laws.

7 Lee December 30, 2015 at 9:21 am

come on now… if you start using objective data and rational analysis to evaluate the efficacy of specific laws– you will invalidate most laws on the books.

also, what’s the legal/constitutional basis for any curfew law? You are depriving an entire class of citizens of substantial liberty & freedom of movement… with no demonstration of individual wrongdoing or application of judicial due process.

8 Nathan W January 2, 2016 at 5:29 am

Children also can’t vote and are disallowed from opting out of school.

What freedom the law allows us comes at 18, no?

9 Bill December 30, 2015 at 9:37 am

Curfew laws are like laws prohibiting

Spitting on the sidewalk, or loitering, or playing loud music.

An excuse to disrupt a group of youths, arrest someone because you suspect they did something else,

Or because the whi’folks weren’t invited to the Pahty.

It’s cultural.

Unless its New Years Eve.

10 Quite Likely December 30, 2015 at 9:56 am

Yeah I think this is the real answer. It’s not like the police are regularly stopping people walking down the street to ask for ID and verify that they’re at least 17. It’s just that there are areas of DC where a bunch of black kids like to hang around outside, and the police want to be able to walk up to them and say “you’re violating curfew, get out of here!” rather than having to think of a new trumped up accusation every time.

11 Nick L December 30, 2015 at 4:25 pm

I doubt curfew laws are as racially motivated as you think. Here in St. Louis the expensive suburbs have the same curfew laws as the rest of the city.

12 jdgalt December 31, 2015 at 12:50 am

Hooey. Curfews are about adults’ right to have it be quiet outside so we can sleep. A difference which I believe is important enough to accept a miniscule increase in violence.

13 Ray Lopez December 30, 2015 at 9:50 am

Reminds me of the anecdote I heard that taxi drivers deter more crime than police, simply because there are more of them.

14 Pshrnk December 31, 2015 at 1:04 pm

How does your girlfriend deal with her curfew?

15 ZZZ December 30, 2015 at 9:50 am

I’d like to know how the overall total number of shootings changes and if there is a corresponding decrease in shootings at other times. Because curfews are imperfectly enforced you don’t have a clean cutoff in the number of teens on the street, the numbers will decline in the hours after the curfew takes effect. It could be the entire curve of teens on the street is shifted and shootings that would have occurred between 12 and 1 are now occurring between 11 and 12.

16 Urso December 30, 2015 at 11:15 am

Or perhaps the city fathers realized that the 11 pm-midnight hour was more dangerous for youths after September 1st (due to more gunshots), and therefore it was imperative to get youths off the streets at that time.

I don’t necessarily believe that, but it’s certainly possible, and it doesn’t even appear to have crossed AT’s mind.

17 charlie December 30, 2015 at 11:36 am

“Also what are the ages of those typically arrested on the basis of ShotSpotter alerts?”

has anyone every been arrested based on one of these alerts?

Better story. On sunday when I called in dirt bikers it took dc 911 10 minutes to figure out where “M st and the Key Bridge” is located.

18 Moreno Klaus December 30, 2015 at 11:48 am

And they say US is the land of freedom LOL ….

19 dsgntd_plyr December 30, 2015 at 11:50 am

“The use of ShotSpotter data is innovative and avoids some problems with issues of police enforcement. Calls to 911, however, don’t show the same pattern as the ShotSpotter data which is worrying.”

Snitches get stitches.

20 Aaron J December 30, 2015 at 12:00 pm

Don’t kids go back to school around September 1? Wouldn’t that be the much better reason why there is less human traffic on the street than the curfew. I don’t think everything is ceterus paribus here.

21 Cooper December 30, 2015 at 12:50 pm

By what mechanism would juvenile curfews increase crime?

There might be a correlation but I’m having trouble understanding the causation.

Maybe only the bad guys are running around late at night now that the good guys are in bed. Somehow that leads to more crime? Does the mere presence of good kids on the streets decrease shootings?

22 Aaron J December 30, 2015 at 1:21 pm

The idea is that the curfew convinces noncriminals, who normally would be on the street, to stay in. As a result there are fewer witnesses so criminals face less of a deterrent affect.

I think there are problems with this paper (see above), but that’s the idea.

23 chuck martel December 30, 2015 at 5:28 pm

Making it illegal to be out and about is guaranteed to increase crime since that wasn’t a crime before.

24 Rammar December 30, 2015 at 1:28 pm

“Just the opposite. Using data on gunfire incidents from ShotSpotter (acoustic gunshot sensors that cover the most violent neighborhoods in D.C.), we find that after the curfew switches from midnight to 11:00 p.m., the number of gunshot incidents increases by 150 percent during the 11:00 p.m. hour.”

It’s almost as if shooters get cold in the winter too.

25 Sbard January 1, 2016 at 3:35 am

Do cars still backfire? I don’t think I’ve ever heard it witnessed one do so. It sounds like one if those old timey car issues like dealing with carburetors or tuning an engine as a regular part of automotive maintenance.

26 Nathan W January 2, 2016 at 5:34 am

Once you’re already breaking the law (psshaw, who pays attention to curfews), why not go the whole nine years and shoot someone?

I don’t think people actually think like that. But once they are already criminals for doing innocuous things like smoking a joint or going for a walk late a night, the step to higher level criminality which is more obviously wrong is a far easier step to take.

Comments on this entry are closed.

Previous post:

Next post: