Thread by @ajc730

Here is a thread in which I try to summarize what we know thus far about the cause of the recent rise in gun violence in the U.S. In my view, we can rule out some stories but the picture is not very clear and, as far as I'm concerned, many theories remain in play. 👇

1. The U.S. homicide rate began to tick up slowly in 2015, especially in some cities (e.g., Philadelphia and Chicago). So, for a number of cities, the homicide increase represents a speeding up of a pre-existing trend. Explore the data here: jacobdkaplan.com/crime.html#sta…

2. Via @ZaidJilani, this extraordinary rise in homicide is fairly unique to the U.S. We don't see the same thing in Canada or Mexico or even El Salvador. This is inconsistent with general explanations like economic hardship and pandemic-induced stress. inquiremore.com/p/stop-blaming…

3. Via an analysis by @JohnFPfaff, this doesn't appear to be an artifact of "defunding" the police (which was uncommon) or of criminal justice reforms enacted shortly before the pandemic. The homicide rise seems to have been fairly uniform across cities:

https://twitter.com/JohnFPfaff/status/1378572992024821763?s=20

4. Via @germanrlopez, the homicide rate doesn't seem to rise immediately after the pandemic but it does skyrocket over the summer around the same time as the killing of George Floyd and the ensuing protests: vox.com/2020/8/3/21334…

5. However, via some great detective work by @No_Little_Plans and @Crimealytics as well as Jens Ludwig, there appears to be a rise in gun-carrying that begins alongside the pandemic and, critically, begins ***before*** the killing of George Floyd and the summer protests.

Why do we think there is more gun carrying? Because in March and April police start seizing massive numbers of guns despite making fewer street and car stops and executing fewer searches.

6. There's also evidence that people started buying more guns during the pandemic. While, in general, crime guns tend to be fairly old, more guns in circulation creates greater risks for communities that are already struggling with endemic gun violence. nytimes.com/2021/05/29/us/…

There is a terrific and hugely important working paper by @MWillJr which shows that gun proliferation can have extremely different impacts on Black and White communities. We could be seeing, in part, something along these lines today: morganwilliamsjr.com/wp-content/upl…

So how do we make sense of this? Is this the result of "de-policing"? Maybe. The pandemic led to fewer police on the street and police pulled back from making unnecessary arrests in an unusually visible and official way: thehill.com/homenews/state…

At the same time, while the legitimacy crisis of the summer and the effects of the defund movement on police morale probably didn't help, the groundwork for today's retaliatory violence seems to have been laid before anyone had heard of George Floyd or Derek Chauvin.

Is this a response to broader social forces? The argument is articulately described by @patrick_sharkey who notes that in disadvantaged communities, the destabilizing effects of crisis can induce people to engage in an arms race, preparing for the worst. theatlantic.com/ideas/archive/…

If Pat is right, why does the rise in violence seem to be greater in the U.S. than in Mexico which certainly has its share of poverty, gangs and a lack of police legitimacy? In Mexico, a lot of violence is directed by large criminal enterprises, rather than small crews...

... which means that the social forces put into motion by the pandemic in Mexico may be filtered, to a greater degree, by the cartels. In the U.S. where gangs are small, community dynamics may loom especially large.

To sum up, there are probably a number of reasons for the increase in violence. While I think we can rule out reductions in police funding, I don't think we can rule out that some form of de-policing (or even just perceived de-policing) explains some of what we're seeing.

But it definitely doesn't look as simple as "the protests caused the violence." And any explanation needs to account for the effects of gun proliferation and carrying which pre-dates the killing of George Floyd.

As always, we should continue to refine and adjust our views as more data comes to light.