Hello from London! My dog Chula — pictured above — is on her own vacation at my mom’s house. She gets twice as many treats there as she does at home, and she gets to consume them in a big, sunny backyard. So, we are both enjoying the summer.

I’m writing to share two things I recently posted elsewhere.

My call for more cameras

The first is an op-ed for the Houston Chronicle [gift link], making the case for the installation of cameras along the city’s beautiful run/walk/bike trails. I’m, frankly, fed up with reports of violent attacks along these trails. We don’t have to live like this! Cameras help law enforcement catch offenders quickly. This takes would-be repeat attackers off the streets quickly, and also deters crime from happening in the first place. We have strong research evidence of this deterrent effect. Cameras are much cheaper and more effective than alternative strategies. Yes, we need to protect privacy. But — despite what you might expect based on headlines about recent privacy violations — that is not hard to do. If your city is looking for help, I suggest contacting NYU’s Policing Project.

Related: I’m writing this newsletter from London, where CCTV cameras are everywhere, along with signs advertising that they’re filming. While I’d prefer if folks here were less judgmental about my tea preferences, the UK is hardly an authoritarian dystopia.

My op-ed:

Like many Houstonians, I’ve followed recent news stories about violent attacks on this city’s beautiful running trails. Those attacks unnerve me.

As a woman, I’ve wondered why there aren’t cameras along the trails to quickly identify perpetrators when such crimes occur. And as an expert in crime and criminal justice policy, I’ve wondered the same thing.

Economics researchers like myself use randomized controlled trials and “natural experiments” to measure the real-world impacts of policies and programs. Such studies show that surveillance cameras reduce crime in the areas where they are deployed. Careful studies across multiple countries show crime reductions of 20% to 25% in areas with camera systems. The mechanism is straightforward: Cameras increase the probability that criminals get caught. Decades of research confirm that certainty of punishment deters crime far more effectively than severity of punishment. Cameras put this important insight into action.

The sad reality is that most perpetrators get away with their crimes. Across the United States, clearance rates (the likelihood that a reported crime results in an arrest) for violent crimes hover around 50 percent. In Houston, only 28% of reported violent crimes result in an arrest. Most violent crimes — especially those against women — are committed by someone the victim knows, like a boyfriend or husband. Those sorts of crimes are easy to solve, bringing up the average. But random violent attacks like those on Houston’s trails are extremely unlikely to be solved.

We can and must do better. Cameras can help.

Research from Stockholm's subway system found that surveillance cameras reduced crime by approximately 25%, with particularly strong effects on financially motivated crimes like pickpocketing and robbery. A study of police-monitored cameras in Montevideo, Uruguay, documented a 20% reduction in crime with no evidence of displacement — meaning criminals didn't just move to adjacent blocks. Similar results emerge from San Francisco and Medellín, Colombia. Across these very different contexts, cameras had big deterrent effects on crime. Because they were more likely to get caught, many would-be perpetrators simply stopped committing crime.

This makes cameras strikingly cost-effective. One analysis estimated the cost of preventing a single crime through camera surveillance at approximately $2,000. That is a bargain relative to the cost of hiring additional police officers or the massive social costs that crime imposes on communities — not just direct losses to victims, but reduced property values, diminished foot traffic and kids kept home from school.

Critics worry about privacy, and those concerns deserve serious consideration. The real concern is not simply that cameras exist, but how they are used. People worry about function creep, that tools deployed to deter violence today could be used tomorrow to monitor political protests or enforce controversial federal immigration policies. They worry about disproportionate surveillance in minority neighborhoods. They worry about private companies building vast data networks with unclear accountability.

These are not frivolous objections. History offers examples of surveillance powers expanding beyond their original purpose. Indeed, plenty of recent headlines offer such examples as many cities reconsider their contracts for networked cameras and license plate readers.

But we should also consider the alternatives. Unlike harsher sentencing policies that fill up our prisons but have minimal impact on crime, cameras offer deterrence without incarceration. They increase the certainty of consequences — which actually changes behavior — rather than focusing on punishment after the fact. And camera footage is more accurate than eyewitnesses’ memories, helping to avoid wrongful arrests and convictions.

I am confident that we can install tools like cameras in ways that build community trust. We need appropriate safeguards — clear rules about data retention and access, transparency about deployment decisions and oversight mechanisms to prevent abuse. This requires attention, but it isn’t rocket science. Organizations like the Policing Project at New York University already help government agencies design such safeguards.

As a crime expert, I believe this city’s residents deserve a system that delivers reliable, swift consequences for criminal behavior. Tools that help law enforcement solve more crimes, faster — tools like cameras — are a smart way to fight crime and provide justice to victims.

As a Houston resident who now thinks twice about going out for a walk, I implore Mayor Whitmire: Please install cameras along this city’s trails.

My call for crime economists

Second, Anthropic’s new Request For Proposals got me thinking:

Anthropic has launched a new fund for ambitious economics research projects studying AI-related transitions in the labor market, etc.

My hot take: few people have thought more about how to put those on the margins of the labor market on a better path than crime economists.

When people — especially men — aren’t on a “good” path (education, employment), or are feeling insecure about their place in the world, they tend to cause a lot of trouble — for themselves, their families, and their communities. Sometimes this looks like intimate partner violence or sexual assault. Sometimes it looks like burglary or homicide. This is a first-order problem in the US and around the world.

Crime economists certainly think a lot about how to stop crime, using police and prisons. But we also think about what levers we can pull to deter or prevent crime by putting would-be offenders on a better path (before someone’s first arrest, while they’re in the CJ system, and after their release from prison). Does job training help? Mental health care? Summer jobs programs for teens? Cognitive behavioral therapy? GLP-1s to treat addiction?

As an economist, I’m optimistic about all the ways AI will transform our society for the better. Many new jobs will be created. But any transition brings uncertainty and disruption. Many people will lose their jobs as AI tools get better. Many more will feel insecure as we figure out what’s next.

As a crime economist who has followed the literature on how economic shocks affect criminal behavior, I am confident this will lead to more crime. But I’m also confident that our field has the tools to test innovative approaches to minimize the harm - and maximize the benefits - of the transition that is underway.

Fellow crime economists: If you have an ambitious research idea in this vein, I hope you’ll apply for funding. Projects must be $1M or more (ideally over $5M), so they’re not messing around. Bring your biggest ideas. Partner with state and local governments. Let’s go!

Have an idea but need connections (to researchers, practitioners, or policymakers) to help make it a reality? Email me. I’ll try to help.

I’m on vacation for the rest of the summer, reminding myself what it means to rest and recharge before I jump into my next big endeavor. (This week I was in beautiful Minneapolis, where I spent three sun-soaked days catching up with close friends.) So, I’ll be sharing thoughts here a bit more haphazardly than usual.

For your full “economics of crime” fix, I strongly recommend listening to the Fighting Crime podcast that my Arnold Ventures team launched in partnership with Indio Media. The latest episode digs into the evidence that exposure to air pollution increases violent crime, in real time. The featured study is one of my favorites in the entire public safety space, and makes a terrific conversation starter at even the least academic of cocktail parties.

What I’m reading and listening to:

• I’m enjoying Cate Hall’s You Can Just Do Things, about cultivating a sense of personal agency. This book will break you out of whatever rut you’re in this summer/year/season of life. I’ve been recommending it to friends who are feeling stuck, and I’ve found it motivating even though I’ve already decided to make a big leap.

• “States want to bring Medicaid behind bars. Federal changes make that harder”— An update on the implementation of Medicaid reentry waivers in states across the US. Based on previous evidence that expanding access to mental health care reduces crime and recidivism, I’m interested to see if these waivers reduce violence within prisons, and reoffending after release.

• “Who Pays for San Francisco?” — An exploration of how private money is coming in alongside public dollars to provide government services. I appreciate my friend Rob Reich’s warning that philanthropies are less accountable to the public than government is, but I also see an important role for philanthropic dollars in the public safety space, among others. It’s interesting to see how this is playing out in San Francisco, which was struggling for a while (especially on the crime and disorder front) and is now on a much better trajectory — in part because the investment of private dollars made timely, high-impact investments possible.

More links:

I talked with Jonathan Wroblewski for his terrific Sentencing Matters substack. An excerpt:

Jonathan: Can you talk a little bit more about what you call the risky investments?

Jennifer: John Arnold talks a lot about a two-by-two matrix of funding opportunities. On one axis, you’ve got impact, low or high impact, and on the other axis, you’ve got probability of success, low or high probability of success. In the first quadrant, you’ve got low probability of low impact. Nobody wants to fund that. The opposite quadrant — high probability, high impact — everyone wants to fund those things. But those are unicorns; they don’t come along very often. And so that leaves two quadrants left that philanthropies can go after. One is the high probability, low impact. Because there is a tendency to want to rack up quick wins, there’s an overabundance of philanthropic dollars going to the high probability, low-impact stuff.

Where there’s an undersupply of investment is the low probability, high impact ideas; the moonshots. John was always encouraging us to try to look for the moonshots. It can be really hard to tell up front which those are. So, we have been trying lots of stuff with a failing-fast mentality. One of the projects we’ve been developing over the last couple of years is looking at the effects of GLP-1s on substance use disorder and ultimately time in jail. There’s lots of anecdotal evidence that GLP-1s seem to have this impact; they reduce cravings for drugs and alcohol, but we don’t have the rigorous evidence yet. There are some ongoing clinical trials, but the question of the impact on the ground is quite different. There are lots of reasons this might not work. But if it does, it would be a game-changer in the public safety space. Finding projects like that has been really fun and rewarding.

You can read the full interview here:

Sentencing Matters Substack

The Sentencing Matters Substack Interview: Economist and Executive Vice President of Criminal Justice at Arnold Ventures, Jennifer Doleac

Here in Washington, it’s a rare policy pitch that doesn’t claim to be “evidence based.” But those claims often don’t hold up to even the smallest bit of scrutiny. Behavioral psychologists like Richard Thaler, Daniel Kahneman, and Robert Shiller have shown that for most of us, public problems we face beget policy conclusions first, driven by ideology, po…

Read more

a month ago · 1 like · Jonathan J. Wroblewski

I also talked with Kurt Nelson for the Behavioral Grooves podcast. We discuss a wide range of topics, exploring how economists think about crime, and what the evidence says about what works best to change behavior.

Finally, I joined the American Bar Association’s JustPod to talk about The Science of Second Chances and what economics has to say about how to improve our criminal justice system.

Want more? You can find my book at your favorite bookseller:

Credit: New York Times

A haze of wildfire smoke is blanketing the northeastern United States today. That’s clearly bad for people’s health, and officials are warning residents to avoid exposure to the smoke-filled air for this reason. But did you know there’s also extensive evidence that exposure to air pollution (including wildfire smoke) increases violence?

I discuss this evidence in my book, The Science of Second Chances:

One of the most fascinating (and terrifying) findings to emerge from research in recent years is that exposure to air pollution negatively affects people’s behavior, in real time.

There is now extensive evidence from medicine, biology, and psychology that common airborne pollutants like PM2.5 (fine, inhalable particulate matter) affect how the brain functions, and thus how people behave and interact with each other.

How is this possible?

There are several possible channels through which air pollution exposure might impact crime. One is… pollution’s effects on general cognitive functions like focus and reasoning. This includes the ability to respond rationally in the moment, as well as the ability to recognize (and appropriately respond to) other people’s emotions. Another is pollution’s effect on hormones. Pollution exposure appears to lower levels of serotonin (an important neurotransmitter that has a calming effect) and increase levels of cortisol (which is part of the body’s stress response); both of these effects could in turn increase anxiety, irritability, and aggressive behavior. Pollution exposure also increases inflammation in the brain and other organs, perhaps triggering a fight-­ or-­ flight response. All this biological evidence has made social scientists wonder if air pollution might increase violent crime—­ not simply due to its effects on brain development (as is the case with lead) but at the time of exposure, affecting adults as well as children.

Okay, it’s possible in theory. But what is the evidence that this is happening, in practice?

Measuring the effects of air pollution on people in the real world is more difficult than measuring effects on animals in a lab. In the real world, exposure to air pollution is often correlated with other factors that could affect criminal behavior. For instance, air quality is usually worse in low-­income neighborhoods, and so pollution exposure is correlated with higher poverty, lower education, and worse health. In order to measure the causal effect of air pollution, apart from these other factors, we need a natural experiment that produces changes in pollution exposure, as if at random.

The economists Evan Herrnstadt of the Congressional Budget Office, Anthony Heyes of the University of Birmingham in the UK, Erich Muehlegger of UC Davis, and Soodeh Saberian of the University of Manitoba in Canada found such a natural experiment. In Chicago, as in many cities, highways run through the areas where people live and work. The locations of these highways are not random. But the exhaust from the cars that drive on those highways does not stay in one place—­ it is carried with the wind to nearby neighborhoods. And the direction the wind blows on any given day changes, in ways that are not related to other factors that affect crime. So changes in wind direction provide random shocks to the pollution exposure affecting people nearby.

Using detailed data on crime and pollution from 2001 to 2012, Herrnstadt and his colleagues found a striking result: On days when the wind blew the car exhaust to the west, violent crime rates rose in neighborhoods to the west of the highway. On days when the wind blew that car exhaust to the east instead, violent crime rates rose in the east. Crime went where the wind was blowing, in real time. Wind direction often changes day to day, so we can be confident that everything else affecting these neighborhoods stayed the same, and it was the exposure to car exhaust that was causing the change in crime. On average, neighborhoods on the downwind side of the highway saw violent crime increase by 1.9 percent. (There was no effect on property crime, consistent with the hypothesis that air pollution affects aggression rather than overall criminality.)

This means that exposure to air pollution is affecting people’s cognition and behavior in ways that make them more violent and impulsive. For those who are at high risk of violence, exposure to more air pollution could make the difference between committing a violent crime or not. Indeed, this evidence suggests that worse air quality is likely one reason for higher crime rates in low-­income neighborhoods. Reducing pollution exposure is one way we could break the intergenerational crime and incarceration cycle for families who live in disadvantaged neighborhoods.

I interviewed one of the authors, Erich Muehlegger, about this study on Probable Causation, back in 2020.

There is also research evidence specific to wildfires:

“The Impact of Wildfire Smoke Exposure on Crime” by Goeun Lee and Seunghyun Lee.

Abstract: Using crime data from 21 major U.S. cities spanning 2007–20, this paper studies the impacts of wildfire smoke on crimes. Wildfire smoke increases concentrations of multiple pollutants simultaneously, which makes it important to use wildfire smoke as a single, unified treatment variable. Our results show that wildfire smoke significantly increases crime, with particularly notable impacts on violent and drug-related crimes. Wildfire smoke leads to increases of 0.49% in overall crime, 0.88% in violent offenses, and 1.35% in drug-related crimes. Our findings show that crime rates surge on the first and second consecutive days of smoke exposure but diminish from the third day onward, possibly due to adaptive behaviors to limit smoke exposure. Lastly, the effects of air quality alerts vary across types of crimes: overall and violent crimes fall but drug-related crimes increase on smoky days with alert days compared to without alert.

In the book, I go on to discuss early evidence on how to mitigate this risk (e.g., what is the effect of putting better air filters in homes, schools, and other buildings?). In my opinion, we should be investing in many such pilots and measuring effects on violent behavior, not just health and education outcomes. We don’t need to end wildfires or dramatically reduce air pollution to make communities safer — we simply need to reduce exposure to that pollution.

I would not be surprised if schools, jails, and prisons saw an increase in violent incidents over the next few days. (Someone should get the data and measure this!) This has big social costs that we have not paid enough attention to. I’d love to see this change.

I’ve been thinking a lot recently about the value of casting a wide net when looking for scalable interventions to reduce crime. Yes, it is important to make police, courts, and prisons more effective. But if that’s all we’re doing, we’re missing a lot of opportunities — not least because preventing someone’s first crime is way easier than getting them off a criminal path once they’re on it.

If you look at programs in the education, health, housing, and job training spaces, you might notice that they’re targeting largely the same population the criminal justice space is serving: kids and adults struggling with some combination of poverty, family instability, trauma, mental illness, and addiction. Everyone is working to find scalable interventions to put these people on a better path and help them thrive. They might measure outcomes like high school graduation, college enrollment, employment, and wages. Those are important, but not the full story. If a program has put someone on a better path — to more education and higher earnings — it has likely helped them avoid a path to crime and incarceration. Those avoided costs should be considered too. Because incarceration is so expensive, any intervention that keeps someone out of jail or prison pays for itself very quickly. That is useful information for ROI-focused policymakers to know.

At Arnold Ventures (AV), I became a broken record when talking with my colleagues from other parts of the organization: please add crime outcomes to your housing/education/health projects!

In my last post, I began discussing ongoing, AV-funded projects that I’m excited about. Today, I’ll highlight a study of an intervention outside the traditional criminal justice space:

Impacts of the Los Angeles Homelessness Prevention Unit on Criminal Justice Outcomes

PIs: Janey Rountree, Till von Wachter, and Brian Blackwell

AV funding: $99,054, in Q1 of 2026.

Housing instability is a challenge for many people who are arrested and incarcerated. Could interventions that help people find safe, stable places to live prevent crime and criminal justice involvement? This study is one of several ongoing research projects testing this approach.

LA’s Homelessness Prevention Unit (HPU) was launched in 2021 to serve families at high risk of homelessness. In partnership with the California Policy Lab — a fantastic research organization based at UCLA and UC Berkeley — HPU staff use an algorithm to determine which families are at highest risk, then proactively offer them assistance. This includes financial assistance that scales with the household size — on average, about $6,500 to pay for rent, utilities, food, transportation, and similar costs. This is a large amount of money, but if it puts families on a better path it could achieve much bigger savings for the city down the road. (There is previous evidence that targeted cash transfers like this can indeed be cost-effective.) Because policymakers will want to compare these costs and benefits — and consider how the net benefit stacks up against other potential uses of those scarce public funds — a randomized controlled trial (RCT) was added in 2023 to quantify the program’s impact. High-risk families are randomly assigned to receive HPU assistance or not. And then, within the treated group, some families are randomly assigned to receive an extra $2,000. Random assignment of families across these three arms (control, baseline treatment, and the “extra cash” treatment) helps ensure that any differences in families’ future outcomes can be attributed to the HPU program, rather than some pre-existing differences across families.

Of particular interest to me, the PIs will measure this program’s effects on criminal justice involvement, including arrests and days incarcerated. This will allow them to measure the social cost savings of this program, in terms of avoided crime and reduced criminal justice spending, and compare those savings with the cost of the program.

Preliminary results are expected in 2027, with follow-up reports to be published in subsequent years.

New podcast episodes:

In the latest episode of Fighting Crime, host Cristina Quinn digs into cutting-edge research on the impacts of police trainings. You might be surprised that we know very little about which police trainings are effective at improving police outcomes. Most studies that do exist simply survey cops on their way out of the training room, asking what they learned. What we really want to know is if they perform differently on the job as a result of the training. Researchers — in collaboration with forward-looking police departments — are just beginning to test trainings in this way. Check out “How to Train a Cop” to learn more:

And in Fighting Crime’s companion podcast, Field Notes, AV’s Julie James interviews Andy Potter from One Voice United (OVU). Andy spent his career as a corrections officer, and founded OVU to bring that field’s perspective to important policy conversations. In particular, he highlights the ongoing “corrections crisis,” where chronic understaffing in jails and prisons leads to terrible conditions for those living and working in those facilities. Andy makes a powerful case that if we care about public safety, we need to pay attention to this crucial — but often ignored — workforce. Check it out:

What I’m reading and listening to:

• I loved this episode of Clearer Thinking, with Nick Allardice from GiveDirectly. If you’re interested in impact-driven philanthropy — including how to think about maximizing ROI in a world that’s full of uncertainty — it’s worth a listen.

• Nick Thompson recently interviewed Eli Pariser on The Most Interesting Thing in AI. The whole episode is great, but Eli’s answer to the last question (at 39:45) has been on my mind for a few days now. His take: So much energy in the AI space goes into making super-moral AI agents that would never do bad things. But haven’t we learned from thousands of years of human history that that’s a fool’s errand? Perhaps it would be more productive to assume that there will be badly-behaved agents, and focus on building an infrastructure that deters and incapacitates them before they can do too much harm. Do we need a criminal justice system for AI agents? 🤯

• I’m enjoying Joanna Stern’s I Am Not a Robot. It’s a great source of inspiration as I finally have time to learn how to use AI myself. (Note: these newsletters are written entirely by me, for better or worse.)

More links:

I’m gradually putting my Probable Causation podcast archive on YouTube. If you missed any of the past 100+ episodes, this is your chance to catch up! Please like and share your favorites to help others find the show.

I’ll leave you with this throwback to my very first episode, with Chloe Gibbs in April 2019, about the intergenerational effects of Head Start programs on criminal behavior (another high-impact intervention outside the traditional criminal justice space!):

One of my top priorities when I joined Arnold Ventures mid-2023 was to launch a standing, open Request for Proposals (RFP) for strong causal research related to public safety. Most research funding at AV had previously been invite-only, with occasional, targeted RFPs on specific topics. As a long-time academic, I’d become good at playing the networking game typically required by foundations (rules of thumb: find a way to meet program officers, and never submit a proposal without talking to them first), but I hated the opaque processes and relationship-based gatekeeping that pervades the philanthropic space. I was determined to create a more transparent process that made it easy for scholars to send AV their ideas. This reduces frictions, and is better for science. (I also wanted to streamline the RFP itself - no researcher wants to read 10-20 pages to figure out if their project is eligible!)

Fast forward through the hefty logistical lift of setting up a submission portal and external review process: this new RFP launch in the spring of 2024. The eligibility criteria were straightforward: we were looking for strong, causal studies measuring the impacts of US-based interventions related to crime, the criminal justice system, or people with criminal records. And all that was required of researchers was a 3-page letter of interest (LOI).

It’s been very fun to see the wide range of interesting projects that have been submitted since then. In line with my transparency goals, we collaborated with the AV Comms team to find a way to post grants made through this RFP online. You can find press releases with those lists on the AV website: 2024, 2025 Q1 and Q2, 2025 Q3, 2025 Q4, 2026 Q1.

(The releases are based on dates of finalized contracts — which could sometimes be much later than they were actually approved due to long bureaucratic delays on the university side. Related: I’ve always wanted to release a public list of average time from approval to finalized contracts, by university, to make information on such delays more visible to university leadership and prospective faculty hires. It’s truly insane how long some universities take to process and accept external funding; this slows down the work and drives both faculty and funders crazy. Some sunlight on all of this would helpful.)

Many funded projects are what I think of as “workhorse” research. The topics may sound less sexy (though of course I think all research is sexy!) but the projects will still produce useful evidence to guide a field that has, for too long, relied on anecdotes to make decisions. We need to provide more incentives to engage in such research; funding helps with this!

But some projects are especially exciting because they test a novel and scalable approach to long-standing problems. These interventions often involve new technology or medical innovations, or bring creative ideas from other fields into the public safety space. They can sometimes be moonshots: especially low-probability, but high-impact if they work.

Today and in future issues of this newsletter, I’ll share some of the funded projects I am most enthusiastic about, to give you a sense of the current research frontier and what I see as the most intriguing open questions in the public safety space.

First up: a new DNA analysis technique that has become a hot commodity in law enforcement circles.

The Effectiveness of Forensic Genetic Genealogy

PIs: Aaron Chalfin, Romaine Campbell, and Brandon Del Pozo.

AV funding: $4.1 million, in Q4 of 2025.

For this project, the PIs are working with law enforcement agencies in multiple states to measure the value-add of forensic genetic genealogy (FGG, pronounced “fig,” and sometimes referred to as investigative genetic genealogy, IGG) to identify suspects in criminal cases, relative to standard investigative practices. Using a randomized controlled trial at the case level, PIs will “horse race” FGG with what would have happened without it, in terms of the likelihood a suspect is identified, arrested, and convicted (after all, we want to get the right person, not just anyone), and the speed with which that happens. If our goal is to solve more crimes, faster — and it should be! — FGG appears to be a powerful new tool in our collective toolkit. But we need experiments like this to tell us just how powerful it is in practice.

FGG uses DNA analysis to identify perpetrators who are not (yet) in a law enforcement DNA database. (It is also used to identify unidentified human remains, which can provide useful leads in criminal cases and bring valuable closer to families.) It does this by using genetic information uploaded (with consent) by users of websites like ancestry.com, 23andMe, and GEDMatch, looking for full matches to crime scene evidence as well as partial matches that could point to a family member — sometimes a distant family member.

(If your DNA is already on one of those sites, you can opt-in to share it for FGG analysis. See this guide from the Sherry Black Foundation for more on how to become a “genetic witness” in this way. Othram also allows direct uploads to its website, dnasolves.com.)

Such analyses are typically done by private labs like Othram and Bode Technology, and they aren’t cheap — currently about $10,000 per case. So, police departments can’t afford to use FGG for everything. And, as with most new high-tech tools, there is also a potential privacy cost. Not everyone is comfortable using this new form of analysis, going beyond people added by law to government databases. We will need to have many thoughtful, candid conversations in the years ahead about when using FGG is worth it.

To inform those discussions, it will be crucial to have empirical evidence on the benefits of this tool. How much does it move the needle, in practice? Are we talking about a 5-10 percentage point increase in the likelihood of solving a currently-unsolved case, or a 70-80 percentage point increase? Most of us would be willing to sacrifice more for the latter. We’re probably also more willing to accept a reduction in privacy to solve a murder than to solve a car break-in. Does the value-add differ across crime types as well, or is it just the perceived cost?

With the advent of AI, we are barreling toward myriad important and ethically fraught discussions like this one. We will need to get good at working through the tradeoffs. Which tools have a meaningful public safety benefit? Which ones also bring privacy costs, and how large are they? And is there a way to implement each tool that mitigates those costs, to make them acceptable to communities?

This study is a big and exciting step forward in the conversation about FGG. I’m grateful to the law enforcement agencies that are willing to engage in this rigorous pilot, rather than simply assuming the tool will be worthwhile. What we learn in their jurisdictions will benefit the entire field. There is lots of work ahead, for all involved, but I’m eager to see the results (expected in 2030).

What I’m reading and listening to:

• The Art of Gathering, by Priya Parker. I pride myself in being an excellent host and community builder, but want to become better at both. As I’ve written before, events can be super useful and productive, when done well.

• Travel that Made Me — a new podcast by my friends at Indio Media (they also make the "Fighting Crime” podcast mentioned below). Each episode is a long-form interview with someone interesting and accomplished, reflecting on their life through the places they’ve been. A fun listen that’s perfect for summertime adventures.

New podcast episodes:

• In the latest episode of Probable Causation, I talk with UC Berkeley professor Manisha Shah about her fascinating research on intimate partner violence (IPV) in Tanzania. Most interventions aiming to reduce IPV focus on adults, and especially women. Manisha and her colleagues focus on adolescents, based on the hypothesis that it is easier to change someone’s relationship habits and choices when they’re young than when they’re older, and perhaps already tied to their partner via finances and children. These researchers also went beyond the standard focus on women to target men as well — recognizing that men are active participants in these relationships too, and everyone needs to bring their best selves to the table for relationships to be healthy. (This approach can often be unpopular among advocates, who want available resources to go to women and girls. We can’t keep thinking of this as a zero-sum game!) In this study, Manisha and her coauthors run randomized controlled trials testing interventions for young women and the young men they’re dating. The impacts were big and striking. Check out our conversation to learn more!

  

• In the latest episode of Fighting Crime (produced by Indio Media for the Criminal Justice team at Arnold Ventures), host Cristina Quinn digs into the topic of DNA. (Yes, my team and I have been thinking a lot about DNA over the past few years!) Cristina talks with Ashley Spence from the DNA Justice Project, Tiffany Roy from the University of Leicester, David Rausch from the Tennessee Bureau of Investigation, Max Isaacs from The Policing Project, and yours truly. The episode discusses new technological innovations in forensic DNA analysis, like the availability of Rapid DNA machines that speed up analysis; how DNA profiles are generated for criminal investigations, and what information they include; how to think about privacy; and evidence showing that adding people to DNA databases has a dramatic deterrent effect on reoffending. Check out the full episode here:

More links:

I had a blast talking with Meredith Edwards about my new book, for The Curious Introvert podcast. You can listen/watch here:

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As an Economics PhD student at Stanford, I spent years hunting for the natural experiment that would become my job market paper. From my cubicle in Palo Alto I had unrivaled access to top scholars — but almost no visibility into what was happening in the real world. So I scoured newspapers for stories about new programs and policy changes, and cold-emailed the people behind them, hoping one might share data or a foothold for a study. Mostly I hit dead ends and started over. (My lucky break came from a news story about state variation in DNA database laws.) It’s an agonizingly inefficient process, and it’s how the third, fourth, and fifth years of a PhD tend to go — until the stars align, or you give up and drop out.

Fast forward a decade: In the summer of 2023, I joined Arnold Ventures, and my inbox was overflowing. Information that had been rare and precious in academic circles — innovative programs, policy shifts, warm introductions to the mayors and nonprofit leaders and state senators running them — was suddenly everywhere. My policy colleagues found this completely unremarkable, and wondered aloud why rigorous studies of all these interesting interventions weren’t getting done. Did academics not know what the open questions were? They suggested we write detailed research agendas to point the way.

I assured them that wasn’t the constraint. Academics know the open questions perfectly well. What they lack is the foothold — the access and the trust — to answer them. Researchers don’t know practitioners, and practitioners don’t know researchers, and neither side trusts the other. The binding constraint on better research isn’t funding or awareness. It’s relationships. Closing that gap became my primary goal at Arnold Ventures, and I’m now more convinced than ever that a funder’s convening power is the most powerful tool in the kit.

Not all events are created equal

Networking events can, of course, be terrible — we’ve all endured the lukewarm hors d’oeuvres and harsh fluorescent lighting. I’ve always loved the relationship-building side of conferences (it became a running joke that colleagues would find me schmoozing at the hotel bar rather than in the sessions), but even I’d rather visit the dentist than face the standard failure modes: hunting for a seat or a conversation in a sea of people who all seem to know each other already, endless small talk that never becomes real connection, and one person droning on while everyone else scrolls their phones.

And there’s a subtler risk on the funder side. Even if we’re confident we throw a warm, welcoming party, we may just be convening the same people again and again. Pleasant, yes — but if everyone already knows each other, what’s the point? Was that open bar really the best use of limited charitable dollars?

What I tried at Arnold Ventures

I knew early on that events would be central to my strategy for facilitating more and better research. I wanted to host the kind of gathering that would have been useful to me as a PhD student — one that produced collaborations practitioners valued too, and built connections across siloed networks that could pay off in both the short and long term. I didn’t see anything like it in the field at the time, and I had a hunch it would matter. Our two largest bets along these lines were BRIDGE Days and Innovation Days. I’ll take each in turn.

BRIDGE Days

We hosted BRIDGE (Building Research IDeas and Generating Evidence) Days roughly every other week, beginning in spring 2024. Between May 2024 and December 2025 we held 32 of them — the only weather cancellation being, improbably, a Houston snowstorm (not on my bingo card!). The events are ongoing, but the analysis below covers that window.

Each event brought 12 researchers and 12 practitioners together for one day, focused on a single topic where our team saw an urgent need for causal evidence. We ranged widely: DNA in investigations, supporting victims of violent crime, employer insurance to spur hiring of people with records, electronic monitoring, retail theft, increasing the reporting of sexual assault, scaling mental health care, and lead pipe replacement, among others. Seating was assigned to mix researchers and practitioners at every table, so no one could simply cluster with people they already knew — though they could mingle freely at the closing happy hour.

The day opened with a short primer: what we know in the space (usually very little), and how economists use randomized trials and natural experiments to separate correlation from causation. A practitioner panel followed, surfacing the challenges and novel approaches most on their minds. Those panels always felt too short by design — just enough to show the depth of expertise in the room and get researchers’ minds working. The rest of the day ran on facilitated conversation and breakout groups, each ideally landing on a specific intervention and a way to implement it that would support a rigorous evaluation.

The trust gap was real at the start. Practitioners wanted their expertise respected and had often been burned by overconfident academics in the past; researchers worried practitioners cared more about ideology than evidence. Watching that distrust dissolve over the course of a breakout group was the best part — our carefully curated attendees met the best version of the “other side,” and their sense of what was possible shifted. We closed each day by pointing people toward our standing RFP, emphasizing that strong causal research was the first step to unlocking AV funding to scale what works.

These events were a major logistical lift, but I made the bet deliberately, for three reasons:

• Control. Owning the content and guest list let us structure each day around our own goals.

• Convening power. A funder’s invitation rarely goes unanswered. We used that pull to get busy, high-value people — top experts and decision-makers — into the room.

• Compounding knowledge. The work of deciding whom to invite and what to discuss deepened our own grasp of the issues and players, making us a sharper resource to our networks long after the event ended.

Innovation Days

Even 20+ events a year left many interesting stones unturned — and biweekly was already stretching our internal capacity. Could we fund external partners to run their own events, again aimed at producing proposals for our RFP? I expected a lower average return, but with no internal staff time required, a lower cost too — so plausibly still worth it.

So we posted an open RFP for Innovation Days (a different name, to distinguish them from our internal BRIDGE Days). We received far more proposals than we could fund, and ultimately backed about 30 events across 2024 and 2025 on a wide range of topics. We helped organizers broaden their networks — suggesting practitioners for researchers to invite, and vice versa, with introductions on offer — but were otherwise hands-off on agendas and design. Maybe some partners would build better events than we could! I wanted to encourage experimentation.

Return on investment

These events promised several benefits: warming practitioners to impact evaluation, forging long-term researcher–practitioner ties, seeding a culture of experimentation, and pulling junior scholars into the public safety field. But our primary goal was concrete — generating research collaborations that became viable projects — and those projects would land with us as funding proposals. (We practically begged participants to submit letters of interest.) So our first-order outcome was easy to name: the number of high-quality proposals submitted.

Topics and participants weren’t random, but event timing essentially was — a function of when an idea struck us, presenters’ schedules, and room availability. We exploited that as-if-random timing in a stacked difference-in-differences design: for each event, we compared attendees’ proposal submissions before versus after, using people slated for future events as the not-yet-treated control group. That controls for underlying time trends — academics submit more in June after the spring term, say, which would otherwise inflate the apparent effect of a May event. Stacking across all events averaged the effect over the full set.

The contrast was stark. BRIDGE Days produced about 2 additional high-quality submissions per event in the 10 weeks afterward (and similar results out to 30 weeks). Innovation Days produced a precise null — completely ineffective at generating the collaborations we’d hoped for, at least in the short run.

Did Innovation Days have no value at all? Not necessarily. But new research projects were the point, so we pivoted: we pulled the Innovation Day RFP and redirected the resources. We took our own oft-repeated advice to fail fast.

Going forward

This is a small slice of my team’s convening strategy, and to be clear, we were just trying stuff — none of us are professional event planners. BRIDGE was our first, best attempt, and surely improvable. But it gave us a benchmark: in its current form, generating one new high-quality research collaboration cost about $35,000. That figure lets us compare BRIDGE against other events and partnerships we might try — keeping our eye on testing ideas and finding scalable solutions, rather than rationalizing ineffective strategies. (People told us they loved the Innovation Days, which might have given us an excuse to keep them going.)

I remain convinced that the binding constraint on progress, from research to policy, is relationships. We all live in bubbles, and getting out of them — talking to people with different vantage points and pressures — helps on many fronts. Here it serves a very practical end: helping researchers and practitioners share what they know and find ways to work together. They often share the big goal (safer communities) but bring different strengths (research methods, institutional knowledge) and face different short-term pressures (publishing, budgets, reelection). Showing that we can and want to help each other is how trust gets built — and trust is what leads to more collaboration.

Still, not all convenings add value. I was genuinely surprised the Innovation Days returned nothing; I’d braced for a lower return, not zero. It’s a frustrating reminder that there’s a limit to what any funder can do in-house, and that scaling impact will take real trial and error. I’m eager to keep experimenting.

My hunch is that the standing RFP was a crucial complement to BRIDGE: attendees knew funding was waiting if they pursued an idea sparked at the event. Targeted, time-limited RFPs, by contrast, mostly serve as a roll call — they reveal who’s already working on a topic but rarely spur new work, which takes time and relationships scholars may not yet have. For the people most likely to chase a new idea — PhD students and junior scholars — real-world connections are the better catalyst. Money helps, but a connection that sparks an idea, which becomes a great paper, is far more catalytic on the research side. And catalytic investments are the whole ballgame in philanthropy.

New podcast episodes:

Probable Causation

The latest episode of Probable Causation features Juan Vargas, an economics professor at Collegio Carlo Alberto and the University of Turin. We talked about the unintended consequences of a Colombian policy announcement that promised to pay people to stop growing coca (the plants used to make cocaine), beginning on some future date. The goal was to incentivize people to stop growing that crop. The result? Farmers raced to start growing it, to increase their odds of receiving those future incentive payments. This one policy announcement undid decades of progress against the drug trade. Check out my conversation with Juan for more!

Fighting Crime

Over the past year, my team at Arnold Ventures has been working closely with Jonathan Coates and his London-based Indio Media team to produce two new podcasts. Our goal is to change the public conversation about public safety, to one focused on innovation and evidence over ideology. I wrote a LinkedIn post with a bit more of the backstory. (TL;DR — I met Jonathan at an event and he convinced me that AV should be a media company. Again, events can be catalytic!)

Please check out these new shows wherever you listen to podcasts; new episodes are posted on alternating Thursdsays. If you like them, help us spread the word by sharing with friends or leaving a review. I’m so proud of how these have turned out and hope you enjoy them.

• Fighting Crime, hosted by Cristina Quinn. A narrative discussion of pressing problems in the public safety space, and new, innovative approaches that might solve them.

  • Episode 1: Why Don’t People Leaving Prison Get Jobs?

  • Episode 2: Little Scandinavia: An American Prison Experiment

    

• Fighting Crime: Field Notes, hosted by me, Julie James, and Kevin Ring. Episodes feature long-form interviews with the most interesting people in today’s public safety arena.

  • Episode 1: Fixing Broken Prisons, with Mike Thompson

  • Episode 2: How Lead Exposure in Children can be Fixed, with Robbie Barbaro

More links:

Jonathan Wrobleski wrote a thought-provoking review of my new book in his Sentencing Matters Substack.

Crucially, Doleac tells us, the economist would insist on treating their own ideas as mere hypotheses, not moral imperatives or self-evident truths. One of the central themes of Second Chances is that criminal justice policy making can look more like a science lab and less like a press or political office, and when it does, the results will often be less crime at lower cost. Doleac walks through example after example in which policies that sounded tough or compassionate or “common sense” turned out, once tested, to have no effect on crime — or even made things worse. She shows how economists use randomized trials and natural experiments — staggered rollouts, eligibility cutoffs, geographic borders — to separate what we think a policy does from what it actually does in the world. The goal is sound policy: less crime, more justice, at less cost.

And I love his vision of an iterative policy-making process that mirrors regular tech improvements:

This is where my mind wonders back to the Apple developers conference. Each year, Apple doesn’t just unveil shiny hardware; it releases a new version of its operating systems. There’s always a list of changes: bugs fixed, security holes patched, features added, old code eliminated. Some updates are big, some are minor, but the assumption is that the system is never finished. The job is to keep iterating.

Doleac helps us imagine the equivalent of an annual “Justice Developers Conference.” It could be a gathering not just of criminologists or economists — those gatherings actually already take place now — but one where DOJ, other federal and state policymakers, sentencing commissions from across the country, legislators and their staff, and others gather with economists and criminologists not to announce the latest crackdown, but to discuss research and roll out “Criminal Justice 17.0” — a set of evidence‑based updates:

• This diversion program was tested in three cities and cut new charges in half for eligible defendants, so we’re expanding it.

• This sentencing enhancement for commonplace technology no longer explains any variation in risk, so we’re retiring it.

• This reentry program that sounded great on paper didn’t move rearrest rates at all, so we’re sunsetting it and reallocating funds.

Read more here:

Sentencing Matters Substack

The Sentencing Matters Substack Book Review: The Science of Second Chances, by Jennifer Doleac

Last week, Apple held its 2026 Worldwide Developers Conference (WWDC), the last one presided over by outgoing CEO Tim Cook. As usual, Cook and his colleagues announced new products and new features for existing ones. The point of these conferences — Apple’s and every other major tech company’s — is to wow us, to convince us that the next wave of technol…

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3 months ago · 5 likes · 1 comment · Jonathan J. Wroblewski

For many years, I’ve been following the work of Callisto, a tech-based platform designed to address gender-based violence like sexual harassment and sexual assault. A primary challenge in this space is that most cases become “he said, she said” scenarios. When only the victim and perpetrator were present, it is very difficult to prove that anything nonconsensual occurred (especially if the bar is “beyond a reasonable doubt,” which it is in criminal cases). This means that most cases are never reported to authorities and most perpetrators never face consequences for their actions. And so, harmful (even criminal) behavior continues.

Enter Callisto, where survivors can save an encrypted, time-stamped account of what happened, while they decide whether and to whom they want to report the incident. That alone is super helpful, as people often question delayed allegations (if this terrible thing really happened, why didn’t you say something at the time?). Even more helpful, Callisto notifies survivors if anyone else files a report naming the same perpetrator (matched via email, phone number, social media handle, or other identifying information that the survivor provided). A lawyer serves as an intermediary for any next steps to ensure such matches are made responsibly. Matches across reports are super helpful in those “he said, she said” cases. One case can feel flimsy — even to the survivor. Maybe it was just a misunderstanding or a bad night? But if six independent reports are made against the same perpetrator, suddenly everyone has more confidence in each one. Those reports are stronger together than they were alone.

I was originally interested in this platform as a potential solution to the problem of sexual harassment in academia, where Title IX offices have proven pretty useless. Perpetrators know that if they harass a student or junior colleague based at a different university (at a conference, for instance), no Title IX office will see itself as having jurisdiction. Callisto could fix this loophole, in addition to providing more evidence through the time-stamped reports and matching system.

Over the last few years, I’ve been thinking about whether a platform like Callisto could also help increase reporting of sexual assault cases to police, and the likelihood that perpetrators are prosecuted and convicted. (As we know, increasing the probability of consequences is the key to deterring crime.) Innovative, tech-based platforms like this could provide traction on problems that have historically seemed impossible to address.

One limitation is a lack of funding. Such platforms are unlikely to make billions of dollars, so are not interesting to venture capital firms. Callisto was originally designed as a service that universities would pay for, but it turns out that universities do not want to pay for bad news about how many of their students are being harmed. (University lawyers are quick to note that their liability is lower if they do not have this information. Yes, I’ve become a bit cynical about academia.) Callisto is now a nonprofit, dependent on philanthropic dollars, though I think there are paths to sustainable revenue streams. For instance, perhaps Callisto could license its platform for use on dating apps or ride-sharing platforms as a way to improve user safety.

The Fund to Prevent Sexual Assault

Jess Ladd, the original founder of Callisto (she left that organization a few years ago) has now teamed up with Kristin Hatcher to spur other innovation in this space. This dream team recently launched a new, exciting venture: The Fund to Prevent Sexual Assault.

The Fund hosts an incubator for smart, scalable, tech-based approaches to reducing gender-based violence. Their initial request for proposals surfaced many smart and creative ideas, which they narrowed down to three start-ups that now form the Fund’s initial cohort. As part of the development process, founders are expected to pilot their approach in the real world, with a rigorous impact evaluation. With this focus on impact built in from the start, the Fund encourages innovation, experimentation, failing fast, and trying again. Many of the cool ideas it funds probably won’t work. But some will! Their goal is to find and scale the high-impact ideas quickly. Along the way, they’ll build a community of practice — talented builders who are focused on addressing sexual assault. That community will learn from each other and root each other on. And the Fund will demonstrate that funding is available to those who want to use their talents to address this big social problem.

There are many potential ways to reduce sexual violence. The Fund’s first cohort is focused on one important and fresh angle: interventions targeting young men who might become perpetrators. The goal is to meet those young men where they are and guide them toward a better path — one where they learn how to form healthy and fulfilling relationships.

Approaches like this can be controversial in the survivor advocacy community. Many advocates want resources directed to survivors, not perpetrators (or would-be perpetrators, in this case). This zero-sum thinking clearly holds us back. If we can help people avoid doing harm, that doesn’t just help them, it helps their would-be victims as well. (This is true in the broader public safety space too, of course. It’s best to keep an open mind about the most effective way to solve tough problems.)

The three start-ups in the Fund’s first cohort are listed below. (Descriptions are copied directly from the Fund’s website — you can find more info there.)

The Kaisa Project, built by Adam Dodge and Kathryn Kosmides.

A creator-partnership model that works with leading online gaming streamers to introduce conversations about sexual assault prevention with their audiences. The project will collaborate with up to 15 creators to develop short-form video and livestream segments that model respectful behavior, challenge harmful norms, and equip young audiences (particularly boys ages 11-14) with practical language and scripts for navigating peer interactions online and offline.

is this ok?, built by Priya Nakra.

ito (is this ok?) is an anonymous, real-time consent reflection tool designed for teens and young adults navigating ambiguous interpersonal situations. When someone is considering making a move – like kissing or going further physically or continuing when signals are unclear – the tool guides them through a short reflection process that helps them interpret contextual cues, assess whether consent is present, and identify respectful next actions. The system includes built-in “Stop Moments” that flag high-risk scenarios (e.g., intoxication, prior refusal) and prompt users to pause and reconsider before proceeding.

Teach Us Consent, built by Chanel Contos.

Teach Us Consent is launching a youth-focused social media initiative designed to reach young teens where they are – online. The project will develop engaging, relatable, and educational content that equips teens with practical knowledge about consent, healthy intimacy, and respectful relationships, while directing audiences to a broader set of accessible educational resources and tools on our website. Building on a proven large-scale communications model developed in Australia, the initiative aims to normalize conversations about consent within youth culture and make prevention knowledge widely visible, relevant, and actionable.

I’m super excited to see how this first cohort develops, and where the Fund goes from here. And this endeavor has gotten my team thinking about other issues in the public safety space that could benefit from dedicated incubators like this one. Innovative, scalable solutions that make communities safer — especially ones where the path to scale could be a profitable business — are sorely needed. I’m excited to think more about this in the months and years ahead.

What I’m reading and listening to:

• “Privacy through a cop’s eyes” — another excellent episode of The Political Orphanage podcast.

• Atlas of Innovation — IFP’s delightful new index of “funding mechanisms suited to frontier R&D.”

• “Meet Splash: Rescue otter helps law enforcement agencies crack cold cases” — a fun reminder to think outside the box when looking for ways to solve more crimes, faster.

More links:

The Corrections1 Book Club recently reviewed my new book:

In her book, “The Science of Second Chances,” author, economist and vice president of criminal justice at Arnold Ventures Jennifer Doleac brings a perspective that challenges the way we understand reform and the opportunities that lie ahead to truly help those within the system, strengthen families and build communities while pursuing alternatives that result in better outcomes.

Over the decades, there have been countless attempts to determine the causes of criminal behavior, the effects it has on society and alternatives to incarceration. How can people be held accountable while upholding the rights of all citizens? How can broken initiatives be aligned when goals for reform are inconsistent, political and poorly communicated? There is no simple answer, and often even the best solutions do not work overall. Taking a deep dive into the economics of criminal behavior and criminal justice reform policy, the author uses an unbiased, scientific approach while keeping the reader engaged with a narrative that is educational and easy to follow.

I joined fellow skeptic Michael Shermer on the Michael Shermer Show to talk about what works to improve public safety.

America’s criminal justice debate usually gets reduced to two options: abolish the system or lock everyone up forever. Economist Jennifer Doleac thinks the data point somewhere else entirely.

In this episode, Michael Shermer speaks with Doleac about what rigorous research can tell us about crime, punishment, deterrence, prison reform, and public safety.

Doleac argues that America has built much of its criminal justice system backwards: too little certainty of being caught, too much faith in long prison sentences, and not enough testing of what actually works.

Listen to the full episode here!

Subscribe now

In July 2023, I left my tenured position as an economics professor to join Arnold Ventures (AV) — a philanthropy focused on evidence-based policy. I was tapped to lead their Criminal Justice program, with two broad goals: (1) raise the bar for what counts as research evidence (i.e., bringing an economist’s obsession with distinguishing correlation from causation), and (2) reorient AV’s policy priorities around the highest-impact ideas.

Since then, I’ve built a fantastic team and an ambitious strategy — facilitating more and better research to figure out what works, then investing in policy development and advocacy to bring effective interventions to scale across the US. And I’ve been thrilled to see how well that strategy has worked.

My team is changing the policy conversation about public safety in at least two big ways:

First, we’re highlighting the importance of innovation and failing fast as the way to find solutions to tough problems. Good intentions aren’t enough. Most good ideas won’t work, but some will. We need to try lots of new things, but stay humble as we search for those high-impact needles in the good-idea haystack.

Second, based on lots of existing evidence about how to reduce crime, we’re shifting attention from severity of punishment (longer sentences) to certainty of punishment (solving more crimes, faster). The latter has a much higher ROI, as I wrote about here.

Economists love helping people allocate scarce resources more effectively, and it’s been a joy to do this in the public safety arena. (For more detail — on what we know and how the economics toolkit helps us learn more — check out my book, The Science of Second Chances: A Revolution in Criminal Justice.)

Over the past three years, I’ve learned a ton about the criminal justice policy and advocacy spaces, how they interact (or don’t) with the research world, and what the primary constraints are in the research-to-impact pipeline. I now know most of the key players in this space, including a wide variety of organizations doing incredible work. And I’ve learned a lot from Laura and John Arnold about how to deploy capital most effectively. With their guidance, I’ve sharpened my thinking on the role of philanthropy (which I honestly had never thought much about before 2023).

Here we are, in June 2026, and I’ve decided it’s time for another leap.

I told my team earlier this week that I’m leaving AV this summer. I’m so proud of what I’ve built here, but I’m eager to seize the momentum we now have in this space. I want to continue all the work I’ve done — in academia and at AV — to build this field further and have even more of an impact on the ground.

The Arnolds put incredible resources into this space (evidence-based public safety), but they can’t do it all themselves. I want to persuade other high-net-worth individuals to invest in an innovative, ROI-focused public safety strategy — one that focuses on impact over ideology. Such a strategy would pilot outside-the-box ideas like GLP-1s to treat addiction, better diagnostic tests to measure young kids’ lead exposure (such exposure increases violent behavior later in life), and employer insurance to incentivize hiring people with criminal records, alongside fresh ideas to improve traditional institutions like police and prisons. I’m intrigued by the idea of General Managers for important issue areas, and think I’m the right person to do this in the public safety space.

I’m still figuring out the details and will be having lots of conversations in the coming months. But I know it’s time to spin this work out. I want to go bigger and faster, to make more communities safer. I am, of course, feeling extra grateful for my network of friends and colleagues right now — especially those who push me to take more risks, more often. We should all do more of that!

I’ll be using this newsletter to share what I’m thinking about and what I’m learning as I go. I hope you’ll stay tuned.

Onward!

I spoke with fellow skeptic Michael Shermer about my book, on the Michael Shermer Show. You can listen here:

Want more? You can find The Science of Second Chances wherever you buy books.

The traditional nonprofit space leaves a lot to be desired. There is plenty of good intent, but far too little focus on impact and ROI. In a world where most of our good ideas don’t work, and some even backfire, this a recipe for disappointment and cynicism. This is certainly true in the public safety space. My team and I are trying to change this, one grant at a time.

So, I’ll start sharing examples of nonprofits I think are doing amazing work, and deserve more support. If you are someone with the financial means to help, consider this your invitation to do so.

First up: Expanding DNA databases and the use of DNA evidence to solve more crimes, faster.

To change behavior, focus on increasing the probability of consequences

In the US we’ve primarily tried to reduce crime by making sentences longer, in the hopes of deterring crime and keeping dangerous people off the street. But this has turned out to have a pretty low ROI, for two reasons. Most people we’re trying to deter aren’t thinking very far ahead, so the threat of a long sentence doesn’t register when they’re making decisions today. And most people age out of crime as they grow up and their brains fully develop (most of us become less reckless and impulsive by our late 20s); this reduces the public safety value of keeping people behind bars for a long time. (Of course there are exceptions, but those prove the rule.)

We now know that a far better way to deter and prevent crime is to increase the probability of consequences, rather than the severity of those consequences. We’re learning! That’s good news!

The bad news: The probability of getting caught if you commit a crime is pretty low. In the US, clearance rates (a useful though imperfect proxy for the likelihood a reported crime results in an arrest) hover around 55% for homicide. That means it’s essentially a coin flip whether you’ll be arrested if you commit murder. Not good! For other offenses, you’re even more likely to get away with it.

Based on recent FBI data, clearance rates average 44% for all violent crime. Only 31% of reported robberies are solved. Only 25% of reported rapes result in an arrest (and we know the vast majority of these crimes are not reported in the first place). Clearance rates for property crime are even more dismaying: 16% on average. Only 9% of reported motor vehicle thefts result in an arrest. As I often quip, given that low number it’s amazing we all aren’t stealing cars, all the time.

This means that to reduce crime rates, we should focus on solving more crimes, faster. It turns out this solution has broad, bipartisan appeal — my team is seeing lots of action on this front in a variety of states across the US. (More on this in a future newsletter.)

But of course, solving crime is easier said than done. What are practical, scalable approaches we can use to increase the likelihood that criminal offenders face consequences?

DNA provides one answer. I have research from Denmark that uses a strong natural experiment to show that adding people charged with felonies (not waiting for a conviction) reduced future offending by 42%. The effects were even larger for younger groups. This is a huge impact, coming primarily through deterrence (the crime never happened, sparing would-be victims and putting those offenders on a better path as well — they were more likely be working or enrolled in school after being added to the database).

Other research highlights that DNA is useful in property crimes, not just violent crimes. One study randomized a subset of burglary cases to have DNA evidence analyzed and uploaded to CODIS (the federal DNA database in the US). Cases in that treatment group were 18 percentage points (138%) more likely to have a suspect identified and 12 percentage points (120%) more likely to result in an arrest.

From a public safety perspective, these interventions were a huge win! Collecting DNA from more people at risk of committing crime, and from more crime scenes, will solve more crimes that do happen and deter many people from offending in the first place. Because of the big deterrent effect, I genuinely believe this is our ticket out of mass incarceration.

The opportunity

In the US, all states require DNA be taken for felony convictions. The policy frontier is adding people arrested or charged with a felony (not waiting for the conviction, though samples can be expunged if the case is dropped), or adding people convicted of misdemeanors. A challenge to such expansions is huge backlogs in forensic crime labs — analyzing these additional samples would take more resources these labs don’t have. (You might have heard of backlogs of rape kits that that haven’t undergone testing — it turns out this is a problem for other offense categories as well.) Recent updates to (very conservative) FBI guidance make it easier to use Rapid DNA machines that can create DNA profiles in 90 minutes — much better than the previous timeline (typically several weeks). Police can use these machines at their own booking stations, creating DNA profiles that identify individuals alongside the mugshots and fingerprints law enforcement has been collecting for many decades.

This brings us to privacy. What is a DNA profile, you ask? Importantly, this isn’t 23andMe, with all the sensitive information you might be used to seeing there. A forensic DNA profile is a string of numbers that is only useful for matching to other DNA. Like a Social Security number, the individual numbers don’t mean anything, but together they uniquely identify you. Indeed, many people working in this space put their DNA profile on their business cards, to demonstrate that the information is not sensitive.

Of course, we need strict regulations governing what data are collected and how they are used, especially as the science advances and new techniques become possible. (I value the Policing Project’s thoughtful advice on how to balance public safety with civil liberties.) But in the case of CODIS and the use of Rapid machines, these regulations are already in place — the FBI is quite conservative here. DNA databases have been around since the 1990s and there has never been a data breach. (This is perhaps because they don’t contain information of any value to hackers.)

I could go on about the opportunity here, even with these guardrails in place. But suffice it to say that my team has determined that expanding DNA databases is one of the highest-ROI opportunities available in the US public safety space.

If we expand DNA databases to include people arrested for felonies in all US states (this is already current policy in 19 states), then (based on conservative assumptions) we expect at least $7.8B in social benefits during the next 10 years, from crime prevention alone. Other strategies — such as increasing the use of Rapid DNA machines — would likely complement this and have even broader crime-reduction benefits, as they help crime labs speed through forensic sample backlogs.

The path forward

Who is doing the work necessary to seize this opportunity? It turns out there haven't been many organizations focused on this, which is part of the reason we see so much potential for impact. (It fits Rugter Bregman’s Triple-S framework — this issue is “sizable, solvable, and sorely neglected.”)

Here are two organizations that Arnold Ventures supports in this space; I’ll highlight others in future missives.

• The newly-launched Center for Forensic DNA Policy and Practice, at the National Criminal Justice Association, will be the cornerstone of this policy work, assisting states and local agencies in responsibly expanding their use of DNA. They will be a national hub for resources, technical assistance, and policy development. Overseen by Chris Asplen, who has deep expertise in the forensic DNA space, this new Center will ground our and others’ work in the years ahead. I am so excited about this.

• The DNA Justice Project, led by Ashley Spence, educates policymakers about the value of DNA and DNA databases. Ashley is a force of nature, combining a powerful personal story that highlights the value of DNA databases to solve crime, with a deep understanding of research and policy in this space. This makes her a smart partner to lawmakers who want to find a path forward on this issue. (Check out her book, Silent Witness.)

And of course, we need more research to rigorously measure the impacts of new DNA policies and practices! More on some ongoing studies I’m excited about, another time.

What I’m reading:

“A Cheap Fix for Urban Crime” by Elizabeth Glazer in The Atlantic.

“Local Governments Failing Victims of Sexual Assault: Law Enforcement Needs State Support” by Ross Jackson in the Texas Dispatch.

One more thing…

Behavioral Scientist just published an excerpt from my new book, The Science of Second Chances: A Revolution in Criminal Justice.

Want more? Order the whole thing, wherever you buy books.

You might recognize the title (Probable Causation) from my long-running podcast, where I discuss new research on crime and the criminal justice system. In this newsletter, I’ll highlight other issues I’m thinking about and what I’m reading. If you’re interested in evidence-based policy related to public safety, this is the place for you!

If anything below sparks an idea about how we might work together, please get in touch.

One thing I’ve been thinking about over the past week:

Violence against women and girls. I spent last week in London, where the UK government is pursuing a “Safer Streets” initiative that includes reducing violence against women and girls (which they more concisely refer to as VAWG - pronounced “vog”). I attended a research conference intended to inform this effort last summer, and it is still striking to me how unusual that gathering was. Researchers and practitioners who focus on street violence (where the victims are typically men) usually meet in completely different spaces than the researchers and practitioners who focus on gender-based violence (where the victims are typically women). The norms, ideologies, and focus on rigorous evidence differ substantially across these groups. Putting them in the same room made the contrast jarring. How many opportunities have we missed because of these siloed discussions?

In the former (street violence), randomized trials and other rigorous evidence are far more common (though, of course, not as common as I’d like — I’m working on it!). As a result, we’re making real progress across both knowledge and policy. We now know that summer jobs, cognitive behavioral therapy, mental health care, and increasing the probability of getting caught all have meaningful impacts — they reduce violence and put would-be perpetrators (and their would-be victims) on a better path. I and others are working hard to turn this knowledge into policy change on the ground, while we continue piloting and iterating upon other promising ideas.

In contrast, conversations about VAWG (including sexual assault and intimate partner violence) quickly become laments about how little we know about what works to make women safer. Stakeholders simply do not expect or demand the same level of serious, scientific rigor when it comes to programs and policies in this space.

It would be easy to assume this is because we invest less in women more broadly. After all, the state of the scientific literature on women (and their unique medical concerns, like the impact of perimenopause and menopause) is also much thinner than we’d like, something that more and more doctors are raising alarms about. But I think there’s something else going on here too.

There is a strong ideological pull in this space to believe survivors of gender-based violence. I understand and support this general call — we have plenty of evidence that survivors’ claims are too readily dismissed, by everyone from friends and family to law enforcement. But somehow that call to believe survivors has unfortunately morphed into an insistence on believing advocates of programs designed to support survivors. Of course, we know that many good ideas don’t work, and some will even backfire. And yet, when someone like me asks the reasonable question, “what evidence do we have that this program is effective?,” we are met with outright hostility and accusations that we don’t believe survivors when they tell us what they need. This makes progress slower, not faster.

(Note, this type of response from advocates is not unique to this space, but I do think it is far more prevalent and effective here than elsewhere because of the sensitivity around believing survivors’ allegations about the violence they suffered.)

Last week, I had the chance to meet with policy experts like those at BIT, the Ending Youth Violence Lab, the Youth Endowment Fund, and British MPs Alex Davies-Jones and Jess Phillips, who are deeply committed to reducing VAWG and who also see the lack of evidence on what works as an urgent crisis. It is motivating to see them and others working to shift this ideological conversation toward something more pragmatic and productive, where we recognize that good intentions aren’t enough to protect women from violence. Women deserve evidence-based solutions. It’s time for a clear-eyed focus on impact and ROI in the VAWG space.

Onward!

Three articles I’m glad I read:

“‘Law & Order: SVU’ Star Mariska Hargitay’s Rape Kit Backlog Campaign Marks Legislative Wins in All 50 States” by Lexi Carson, The Hollywood Reporter.

“St. Paul’s success solving shooting cases leads to statewide push” by Louis Krauss, The Minnesota Star Tribune.

“Closing Ohio’s Justice Gap” by Jillian Snider, R Street Institute.

Want more? Check out my new book, The Science of Second Chances: A Revolution in Criminal Justice.