Why violence clusters in cities -- and how to reduce it

You are a trauma surgeon,

working in the midnight shift
in an inner city emergency room.

A young man is wheeled in before you,

lying unconscious on a gurney.

He's been shot in the leg
and is bleeding profusely.

Judging from the entry and exit wounds,

as well as the amount of hemorrhaging,

the bullet most likely
clipped the femoral artery,

one of the largest
blood vessels in the body.

As the young man's doctor,
what should you do?

Or more precisely,
what should you do first?

You look at the young man's clothes,
which seem old and worn.

He may be jobless, homeless,

lacking a decent education.

Do you start treatment
by finding him a job,

getting him an apartment,

or helping him earn his GED?

On the other hand,

this young man has been involved
in some sort of conflict

and may be dangerous.

Before he wakes up,

do you place him in restraints,

alert hospital security or call 911?

Most of us wouldn't do
any of these things.

And instead, we would take
the only sensible

and humane course of action
available at the time.

First, we would stop the bleeding.

Because unless we stop the bleeding,

nothing else matters.

What's true in the emergency room
is true for cities all around the country.

When it comes to urban violence,
the first priority is to save lives.

Treating that violence
with the same urgency

that we would treat
a gunshot wound in the ER.

What are we talking about
when we say "urban violence"?

Urban violence is the lethal
or potentially lethal violence

that happens on the streets of our cities.

It goes by many names:

street violence, youth violence,

gang violence, gun violence.

Urban violence happens

among the most disadvantaged
and disenfranchised among us.

Mostly young men,

without a lot of options or much hope.

I have spent hundreds of hours
with these young men.

I've taught them at a high school
in Washington DC,

where one of my students was murdered.

I've stood across form them
in courtrooms in New York City,

where I worked as a prosecutor.

And finally,

I've gone from city to city
as a policymaker and as a researcher,

meeting with these young men,

and exchanging ideas
on how to make our communities safer.

Why should we care about these young men?

Why does urban violence matter?

Urban violence matters

because it causes more deaths
here in the United States

than any other form of violence.

Urban violence also matters

because we can actually do
something about it.

Controlling it is not the impossible,
intractable challenge

that many believe it to be.

In fact, there are a number
of solutions available today

that are proven to work.

And what these solutions have in common
is one key ingredient.

They all recognize
that urban violence is sticky,

meaning that it clusters together

among a surprisingly small number
of people and places.

In New Orleans, for instance,

a network of fewer than 700 individuals

accounts for the majority
of the city's lethal violence.

Some call these individuals "hot people."

Here in Boston,

70 percent of shootings

are concentrated on blocks and corners
covering just five percent of the city.

These locations
are often known as hot spots.

In city after city,

a small number of hot people and hot spots

account for the clear majority
of lethal violence.

In fact, this finding
has been replicated so many times

that researchers now call this phenomenon
the law of crime concentration.

When we look at the science,
we see that sticky solutions work best.

To put it bluntly,

you can't stop shootings
if you won't deal with shooters.

And you can't stop killings
if you won't go where people get killed.

Four years ago,

my colleagues and I performed
a systematic metareview

of antiviolence strategies,

summarizing the results of over 1,400
individual impact evaluations.

What we found, again and again,

was that the strategies
that were the most focused,

the most targeted,

the stickiest strategies,

were the most successful.

We saw this in criminology,

in studies of policing,
gang prevention, and reentry.

But we also saw this in public health,

where targeted tertiary
and secondary prevention

performed better than more generalized
primary prevention.

When policymakers focus
on the most dangerous people and places,

they get better results.

What about replacement
and displacement, you might ask.

Research shows that when
drug dealers are locked up,

new dealers step right in,
replacing those that came before.

Some worry that when police focus
on certain locations,

crime will be displaced,

moving down the street
or around the corner.

Fortunately, we know now
that because of the stickiness phenomenon,

the replacement and displacement effects
associated with these sticky strategies

are minimal.

It takes a lifetime of trauma
to create a shooter,

and decades of disinvestment
to create a hot spot.

So these people and places
don't move around easily.

What about root causes?

Isn't addressing poverty or inequality
or lack of opportunity

the best way to prevent violence?

Well, according to the science,

yes and no.

Yes, in that high rates of violence
are clearly associated

with various forms of social
and economic disadvantage.

But no, in that changes in these factors

do not necessarily result
in changes in violence,

especially not in the short run.

Take poverty, for instance.

Meaningful progress on poverty
will take decades to achieve,

while poor people need and deserve
relief from violence right now.

Root causes also can't explain
the stickiness phenomenon.

If poverty always drove violence,

then we would expect to see violence
among all poor people.

But we don't see that.

Instead, we can empirically observe
that poverty concentrates,

crime concentrates further still,

and violence concentrates most of all.

That is why sticky solutions work.

They work because they deal
with first things first.

And this is important,

because while poverty
may lead to violence,

strong evidence shows that violence
actually perpetuates poverty.

Here's just one example of how.

As documented by Patrick Sharkey,

a sociologist --

he showed that when poor children
are exposed to violence,

it traumatizes them.

It impacts their ability to sleep,

to pay attention, to behave and to learn.

And if poor children can't learn,

then they can't do well in school.

And that ultimately impacts their ability
to earn a paycheck later in life

that is large enough to escape poverty.

And unfortunately,
in a series of landmark studies

by economist Raj Chetty,

that is exactly what we've seen.

Poor children exposed to violence
have lower income mobility

than poor children who grow up peacefully.

Violence literally traps
poor kids in poverty.

That is why it is so important
to focus relentlessly on urban violence.

Here are two examples of how.

Here in Boston, in the 1990s,

a partnership between cops
and community members

achieved a stunning 63 percent
reduction in youth homicide.

In Oakland, that same strategy

recently reduced nonfatal
gun assaults by 55 percent.

In Cincinnati, Indianapolis
and New Heaven,

it cut gun violence by more than a third.

At its simplest,

this strategy simply identifies
those who are most likely to shoot

or be shot,

and then confronts them
with a double message

of empathy and accountability.

"We know it's you
that's doing the shooting.

It must stop.

If you let us, we will help you.

If you make us, we will stop you."

Those willing to change
are offered services and support.

Those who persist
in their violent behavior

are brought to justice
via targeted law enforcement action.

In Chicago, another program
uses cognitive behavioral therapy

to help teenage boys

manage difficult thoughts and emotions,

by teaching them how to avoid
or mitigate conflicts.

This program reduced violent
crime arrests among participants

by half.

Similar strategies have reduced
criminal reoffending

by 25 to 50 percent.

Now Chicago has launched a new effort,

using these same techniques,

but with those at the highest risk
for gun violence.

And the program is showing
promising results.

What's more,

because these strategies
are so focused, so targeted,

they tend not to cost much
in absolute terms.

And they work with the laws
already on the books today.

So that's the good news.

We can have peace in our cities,

right now,

without big budgets

and without new laws.

So why hasn't this happened yet?

Why are these solutions still limited
to a small number of cities,

and why do they struggle,
even when successful,

to maintain support?

Well, that's the bad news.

The truth is, we have not been very good
at organizing our efforts

around this phenomenon of stickiness.

There are at least three reasons
why we don't follow the evidence

when it comes to urban violence reduction.

And the first, as you might expect,

is politics.

Most sticky solutions don't conform
to one political platform or another.

Instead, they offer
both carrots and sticks,

balancing the promise of treatment
with the threat of arrest,

combining place-based investment
with hot-spots policing.

In other words,

these solutions are both soft and tough

at the same time.

Because they don't line up neatly

with the typical talking points
of either the Left or the Right,

politicians won't gravitate to these ideas
without some education,

and maybe even a little pressure.

It won't be easy,

but we can change the politics
around these issues

by reframing violence
as a problem to be solved,

not an argument to be won.

We should emphasize evidence
over ideology,

and what works versus what sounds good.

The second reason why we don't
always follow the evidence

is the somewhat complicated nature
of these solutions.

There is an irony here.

What are the simplest ways
to reduce violence?

More cops.

More jobs.

Fewer guns.

These are easy to spell out,

but they tend not to work
as well in practice.

While on the other hand,

research-based solutions
are harder to explain,

but get better results.

Right now, we have a lot of professors

writing about violence
in academic journals.

And we have a lot of people
keeping us safe out on the street.

But what we don't have

is a lot of communication
between these two groups.

We don't have a strong bridge
between research and practice.

And when research
actually does inform practice,

that bridge is not built by accident.

It happens when someone takes the time

to carefully explain
what the research means,

why it's important,

and how it can actually
make a difference in the field.

We spend plenty of time creating research,

but not enough breaking it down
into bite-sized bits

that a busy cop or social worker
can easily digest.

It may be difficult
to acknowledge or accept,

but race is the third and final reason

why more has not been done
to reduce violence.

Urban violence concentrates
among poor communities of color.

That makes it easy for those of us
who don't live in those communities

to ignore the problem
or pretend it's not ours to solve.

That is wrong, of course.

Urban violence is everyone's problem.

Directly or indirectly,

we all pay a price
for the shootings and killings

that happen on the streets of our cities.

That is why we need to find new ways
to motivate more people

to cross class and color lines
to join this struggle.

Because these strategies
are not resource-intensive,

we don't need to motivate
many new allies --

we just need a few.

And we just need them to be loud.

If we can overcome these challenges

and spread these sticky solutions
to the neighborhoods that need them,

we could save thousands of lives.

If the strategies
I've discussed here today

were implemented right now
in the nation's 40 most violent cities,

we could save over 12,000 souls

over the next eight years.

How much would it cost?

About 100 million per year.

That might sound like a lot,

but in fact, that figure represents
less than one percent

of one percent
of the annual federal budget.

The Defense Department
spends about that much

for a single F-35 fighter jet.

Metaphorically, the treatment is the same,

whether it's a young man
suffering from a gunshot wound,

a community riddled with such wounds,

or a nation filled with such communities.

In each case, the treatment,
first and foremost,

is to stop the bleeding.

I know this can work.

I know it because I've seen it.

I've seen shooters put down their guns

and devote their lives
to getting others to do the same.

I've walked through housing projects
that were notorious for gunfire

and witnessed children playing outside.

I've sat with cops and community members

who used to hate one another,
but now work together.

And I've seen people
from all walks of life,

people like you,

finally decide to get involved
in this struggle.

And that's why I know that together,

we can and we will
end this senseless slaughter.

Thank you.

(Applause)