How admissions to top universities in the US really works as revealed by a simple comparison between one of NYC's top public high schools (Stuyvesant HS) and one of NYC's top private high schools (Horace Mann School). A short thread with some basic descriptive statistics 👇👇 At @StuyNY, a public magnet school where nearly half of students qualify for NYC's free or reduced price lunch program (<$50K for a family of 4 with NYC cost-of-living), the middle 50% of SAT scores are 1490-1560. See: stuy.enschool.org/ourpages/auto/…

In a field experiment in NYC, residents were provided with mundane information about local police officers. The intervention shifted residents’ perceptions of officers’ knowledge of illegal activity, and may have modestly reduced crime in the short run.👇
nature.com/articles/s4158… Each residence in a treated area received a mailer including an outreach card and letter about a neighborhood officer describing mundane information about the officer, such as his/her favorite food, hobbies or why they became an officer.

The main narrative about 2020 is that while murder rose, other crime fell. But people stayed inside more, making it hard to infer anything about public safety. In a new paper, Maxim Massenkoff & I study changes in the risk of violence while out in public.👇maximmassenkoff.com/papers/victimi… We study violent street crimes in the three largest cities in the US. Shortly after the pandemic began, street crimes fell by 30% as the public adjusted to disease risk and lockdowns by spending more time in their homes.

What happens to crime in US cities when police pull back? It depends. When police reduce proactivity for reasons other than a viral incident, most papers don't find a crime increase. But when a pull back accompanies a viral incident, most papers find that crime rises. Citations👇 With respect to pullbacks which are due to dissatisfaction over arbitration agreements, the findings are mixed. See 1) academic.oup.com/aler/article-a… which finds little impact in NYC and 2) academic.oup.com/qje/article-ab… which finds increased crime in NJ.

The progressive prosecutor's gamble is that many offenders aren't nearly as motivated as we think they are, that the CJ system further entrenches criminal identity and that a lighter touch could actually enhance public safety. Could that be right? Thread 👇 Going back to Gary Becker (and even further than that), the cost of committing a crime has been seen as a function of the certainty of punishment and the severity of the punishment. Broadly speaking, research supports the idea that certainty deters more than severity.

The University of Chicago Crime Lab is in the market for a new Research Director! This would be an ideal job for someone who will finish their PhD in Spring 2022. As a Crime Lab alumnus, I could not recommend this job more highly. Short thread 👇
urbanlabs.uchicago.edu/attachments/09… For someone who wants to do research that is tightly linked to policy decisions, this is an incredible opportunity. You will have access to phenomenal data and you will have the opportunity to talk to and learn from high-level policymakers as well as people working on the ground.

Do domestic violence shelters keep the victims of family violence safe? @lrschechter has a new paper which studies the impact of opening a shelter where there were none previously. She finds that DV shelters appreciably reduce intimate partner homicides.👇
dropbox.com/s/lqfkv2lx223v… This is a difficult outcome to study because, at a population level, DV homicides are rare. Lauren is also extraordinarily careful to avoid some pitfalls that arise from using a traditional TWFE model which reduces statistical power.

Nuisance property ordinances deputize landlords to internalize public safety externalities. But are there unintended consequences? @AriaGoles finds that NuPOs reduce the rate at which domestic violence is reported and may increase domestic homicides.👇
ariagolestani.io/wp-content/upl… NuPOs recognize that place managers are sometimes better situated than law enforcement to address public safety issues that have ties to specific properties. There is a great deal of writing about this especially by John Eck. See e.g., oxfordhandbooks.com/view/10.1093/o…

There is a bunch of new research out there on the effects of body-worn cameras (BWCs) worn by police officers. Short thread summarizing four new papers 👇 Experimental evidence using precinct-level random assignment that BWCs reduced citizen complaints and increased the reporting of stops by NYC police officers by Anthony Braga, John MacDonald and James McCabe:
onlinelibrary.wiley.com/doi/abs/10.111…

What happened when the Chicago created a program to divert drug arrestees to treatment? New research by Ashna Arora & @PankaBencsik finds that more people got treatment and public safety improved.
drive.google.com/file/d/1QSxrv7… 👇 When asked how social planners should address the opioid crisis and addiction more generally, many people will evangelize the benefits of treatment. But how do you get the most inframarginal people into treatment? It's a challenge.

A 2017 paper in Nature studies a police slowdown in NYC, and concludes that when the police pulled back, major crimes fell as a result. My co-authors, @dmitre88 & @MWillJr and I have re-analyzed the data and believe this result doesn't hold water. 👇
dropbox.com/s/yuk5pw69kpfo… The coordinated slowdown of police work took place in Dec 2014 and Jan 2015 and was undertaken by NYPD officers in response to a series of events that shook their faith in the city’s political leadership. During the slowdown, summonses issued by police fell citywide by ~ 50%.

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…

How many complaints against police officers can be abated by terminating a few bad apples? Jacob Kaplan and I consider this question in a new paper that is now published in @CPPJournal. We believe the answer is likely to be "not a lot." onlinelibrary.wiley.com/doi/10.1111/17…
Thread 👇 You've probably heard that a very small number of officers are responsible for a very large share of misconduct or citizen complaints. Estimates vary quite a bit but I've seen estimates like 2% of officers account for half of all use of force complaints.

New working paper joint with @benconomics, @emilyweisburst and @MWillJr that considers the race-specific effects of a larger police force in the U.S. nber.org/system/files/w… We find that, in most cities, more police manpower leads to reductions in homicide, with every 10-17 officers hired abating one homicide. In per capita terms, the effects are twice as large for Black versus white victims.

Do police make late shift arrests in order to take advantage of overtime pay? This story is a mainstay of public criticism of law enforcement and reflects broader concerns about the distortionary effects of financial incentives in the US criminal justice system. But is it true? At first blush, it might make sense that officers would want to make arrests at the end of the workday -- overtime pay is fixed 150% of an officer's base pay. As such the "price" of late shift arrests is higher. However, officers also face a labor-leisure tradeoff.

1/ Those of us who have studied the relationship between the size of a city's police force and crime including @emilyweisburst, @mellosteve2 and @ProfEmilyOwens among others are finding our work in the spotlight of late. Here is a tweet which I hope will be useful in sorting 2/ out what we know as well as what we don't know about the effect of police on crime. Views are my own but I am trying my best to summarize what we know absent a political agenda.1) Over the last few decades, when U.S. cities have increased the size of their police force,