Summer of Rage? Summer of Discontent? Summer at Home.

What if the story of violence in the summer of 2020 has nothing to do with partisan politics or perhaps even the police?

I want to pivot a little today from the long-term discussion about a reimagining of police and write about the discouraging rise in homicide this summer of 2020. The idea that seems to have taken hold of the pundits is that the protests are causing a rise in homicides and other violence. I do not quite understand what mechanism is hypothesized to cause this covariation between policing, public demonstrations and homicides. I suppose it is some variation on the theme of what I think of as ‘the Deterrence Constant’. This is the idea that all else being equal, stable policing deters violence is some very predictable way. If you assume constant deterrence, any exogenous shock to policing will cause violence to rise. So, if many officers are diverted from one location to another to respond to demonstrators, this will reduce the deterrent effect of policing. Or so the theory seems to go.

This seems to me to be an explanation in search of a problem. I think what gets confused here is the relationship between deterrence and prevention. There’s a lot more to be said about this, but for the moment let’s focus on what is implied by this hypothesis, that the mere presence of police deters crime and violence and that the absence of police encourages crime and violence. Put another way, this suggest there is a Deterrence Constant where one cop on the beat equals some reduction in crime. Policing in this formulation is just a commodity, where adding one officer removes a specific amount of violence. This is generally how policing is modeled in the economics literature and often by criminologists as well. But violence varies substantially across places and time. And the quality of policing is highly variable too, varying by the officers deployed in a given shift in a given place. There is nothing particularly constant about either policing or violence.

Having fewer police patrolling a place does not by itself predict much of anything, most of the time. What matters is how well those who remain police. I have no idea how deployments were undertaken in response to protests and I’m sure the pundits don’t either. Did the rookies go downtown and the veterans stayed in the precinct? Or vice versa? Were off-duty officers and officers on desk duties called in to patrol the precinct? Or did they go downtown? Policing agencies don’t make their deployment data public, for obvious reasons, so who knows.

Another implication of this theory is that the demonstrations caused the people who didn’t go downtown to significantly alter their usual behavior. Or, put another way, that the demonstrations somehow caused distrust in the police to spike. The idea is that public attitudes toward the police shifted due to the protests and that the same level of policing resulted in a new, lower level of deterrence. I doubt it. While policing quality varies, what does not vary much, or at all, over short periods of time are citizen attitudes about the police. Researchers refer to attitudes and beliefs that are relatively unchangeable as ‘time invariant’. Beliefs about police—how much they are trusted, whether they are fair and equitable, and whether they are seen as legitimate—do not vary. In a large survey we just finished (a repeated cross-section), we asked many residents of high violence places about their beliefs and repeated those questions one year later. There was no change in the average response or even in the distribution of responses. These beliefs are stable (this is a big problem for incremental police reformers, but more on that some other time).

So, if attitudes about police are stable and deterrence is a sledgehammer explanation, what is going on? I think the answer is relatively simple. Violence can certainly be effected by outside forces, and I think that is the case this summer of 2020. But those outside forces do not have to be political in nature. We seem to be looking in the wrong direction because the answer is most likely not political not about policing or demonstrations or anything else particularly newsworthy. Which is why you read about it here instead of in the papers.

First though, we should figure out if violence is actually rising in the summer of 2020. Check out this excellent report from the Council on Criminal Justice. The story is a little murky because of small sample sizes in the number of months after the pandemic (four) and the number of cities with data (less than 40). But just focusing where there is a clear trend, yes, homicides are way up, as are aggravated assaults. Have a look at this graphic which shows homicide is up 37%.

Homicides make headlines, but the key to the story is not in the the data that generates the headlines but in everything else. Here’s the burglary chart:

Residential burglaries are obviously not increasing, and the same is true for larceny and motor vehicle theft.  So, understanding the summer of 2020 means finding an explanation that not only fits where crime is up (violence) but also where it is way down (property crimes).

The key is, as usual, COVID-19. But not necessarily our communal ennui, but rather how it has affected our routine activities. Routine activities theory is a simple model of individual behavior that is not only useful in criminology, but has a clear analog in economics—rational choice. It posits that any individual will commit a crime if there is a suitable target, a motivated offender and a lack of guardianship. Some of the preferences within the model are set by the individual (how risk averse are you, how much do you value whatever illegal thing you want to do) and some are imposed on the individual by external forces (what is my belief about the likelihood of my getting caught and punished). Put another way, the idea is that there is a weighing of expected costs and benefits before a crime is committed.

On spiking homicides and assaults, I think the summer of 2020 is mainly a routine activities story. Young men are stuck at home instead of working or going to school. They are experiencing the same anxiety the rest of us are experiencing, but in neighborhoods with a long history of violence they have the added burden of accumulated traumas, including unresolved disputes. And critically, the people they have serious beefs with are also stuck at home and close by. Imagine someone you loved was killed or shot or beaten and you know (or you think you know) who did it (that is the motivation). You are stuck at home without access to supports, a caring teacher, work for a sense of purpose, or professional supports (that is the lack of guardianship). And the guy who did it is just a few streets away (that’s the target). It’s just a toxic situation.

Now add to the mix easy access to guns. The number of guns purchased since the beginning of the pandemic is astronomical. According to the Trace, the number of guns sold has about doubled since the start of the pandemic, with 2.6 million sold in July alone. These guns leak into to the illegal market and become crime guns. Some are bought for this purpose, but many more are stolen for homes and cars.

What makes this theory most compelling, I think, is that it explains just as well why property crimes are down. Residential burglary in the UK is about equally as likely to happen at night as during the day. In the US, residential burglary is a daytime crime. The difference is due to the lack of civilian gun owners in the UK. In the UK, if you break into someone’s house and they are home, you have a fair chance of simply running away. In the US, you might get shot. During the pandemic, everyone’s routine activities changed, and now they are home, and US residential burglaries are way down. Cars and trucks are parked at home, so motor vehicle thefts are way down as well since your truck is much more likely to be stolen off the street or out of the Walmart parking lot than out of your driveway. Larceny (theft without force) is down for the same reason.

Coda: Guardianship plays a role in all of this, so perhaps changes in policing deployment and deterrence play a role as well. But guardianship comes in many forms, professional supports, a caring teacher and programs like Cure Violence which provide guardianship in a far more precise way to prevent violence then do undirected police patrols.  The point being, we do not need to look only to the police for solutions.

Random Thoughts (On Updating Your Priors)

Modern economics gives primacy to the idea that people can move to better their status, particularly for a job. These moves are portrayed as almost frictionless, but of course the inertia of home is real. But perhaps this is less true for academics, and thus they fail to see their own priors which include many moves for work. A typical academic goes to one school for college, perhaps another for a master’s but certainly a second (or third) for their PhD. Universities almost always demand that an academic find employment (and success) somewhere else before returning to their PhD-granting school. So that means at least one move to a different university before a second move back to their PhD home. In practice, that is a short-cut few have the opportunity to pursue: the more usual route is for an academic to go from PhD to a university for their assistant professor job, and another move around the time of tenure, often right around their pre-tenure review at the end of year three (sometimes to a better school to move up the academic ladder for the ambitious, or laterally for quality of life). Then perhaps another post-tenure move to the most prestigious school you can nest at for the remainder of your career.

It’s a stylized example, but the important takeaway is this: a typical academic will move four to six times for their job between the ages of 20 and 50. That’s a move every 5 to 7 years. And generally these are pack everything you own and move to a new town with new schools for the kids and a new job for a spouse. These are major dislocations with tremendous friction. But they are standard for the academic career trajectory.

So, when an academic sits down to write about the effects of NAFTA or of some other economy-wide job disrupting policy, is it any surprise that they might implicitly include a prior belief that moving for work is just part of a standard career trajectory?  

Coda: for reasons that are not totally clear, people are moving far less today than in the past, suggesting that the expected friction of moving for work is growing, not shrinking. So this disconnect in live experience might be important.


An unlikely story about Bruce Hornsby, who once toured with the Grateful Dead, Tupac Shakur and BLM:

Important reporting from the New York Times on the disastrous effects of the total US failure to invest in prevention as evidenced by the massive number of preventable early deaths of people of color.


It’s impossible to believe that in my twenties war raged in Europe and the west looked away at genocide. Cellist of Sarajevo is the story of both grinding out daily life and fighting back. Arrow is one of the great female leads in a modern novel.


My grad school class in tax policy was a revelation, alternately intriguing and frightening. The premise was that tax policy can effect what you do, who you marry and whether you have kids. Here’s a fascinating graphic from Jacob Bastian who shows how the Earned Income Tax Credit induced one million mothers to find employment.

Musical interlude:

Bruce in Europe.