Connecting big drops in homicide rates and race and ethnicity

A new sociological study finds that homicide rates across different racial and ethnic groups have fallen:

The study revealed that three of the most significant social trends over the past 20 years — mass incarceration, rapid immigration and growing wealth inequality — all contributed to the reduction in the gaps between the white homicide victimization rate and those for blacks and Hispanics.

As a result, the black-white homicide victimization rate gap decreased by 40 percent, the Hispanic-white gap dropped by 55 percent and the black-Hispanic gap shrunk by 35 percent, according to the study to be published Thursday in the April issue of the American Sociological Review…

In fact, the study found that an influx of immigrants actually decreases homicides. “People who decide to come here are not people with strong tendencies toward violent crime,” Light said. “They are coming here for educational opportunities, employment opportunities and opportunities to help their families.”…

The study also showed that the increasing racial/ethnic disparities in incarceration rates were associated with significant reductions in black-white and black-Hispanic homicide victimization rate gaps. However, the authors were quick to caution against drawing the conclusion that even more incarceration would produce even more benefits because the findings have to be viewed in a larger context.

There are several matters of public perception that this study seems to address. Many are not aware of these declines and instead think crime has risen (see earlier posts here and here). Or, how about the data on immigration on crime where higher rates of immigration lead to lower homicide rates? Or, the roughly 35-40 percent decrease in the homicide rates for whites, blacks, and Latinos?

Thinking more broadly, what would it actually take for the American public to change their perceptions about crime? Could this sociology study help convince average Americans that violent crime rates have significantly dropped in recent decades? Would the media have to stop highlighting violent crime? Would the entertainment industry (movies, TV, video games, books, etc.) have to become less violent? Thinking about this particular study, perhaps positive changes to race relations would help…

Crime down in US but more mass shootings

What explains why violent crimes are down in the United States but public shootings are up?

The FBI attempted to narrow the definition in a 2014 report that focused on “active shooter” situations, defined as shootings in which an individual tried to kill people in a public place, and excluding gang- or drug-related violence. The agency found that 160 active-shooter incidents had occurred between 2000 and 2013, and that the number of events was rising. In the first seven years of the period, the average number of active-shooter incidents per year was 6.4. In the final seven years, the annual average rose to 16.4.

In these 160 shootings, 486 people were killed and 557 were wounded, not including the shooters.

The rise in active-shooter events bucks the general trend toward less violent crime in the United States: Overall violent crime dropped 14.5 percent between 2004 and 2013, according to the FBI…

Meanwhile, a just-released study finds that although the United States has just about 5 percent of the world’s population, the country has 31 percent of the world’s mass shooters. The reasons for these numbers are complex, researchers say, but the data suggest that the availability of guns, and perhaps the American obsession with fame, may be to blame.

The mass shootings are interesting in themselves but this is tied to a larger question about the levels of violence in the United States that has intrigued social scientists for decades. For example, in graduate school I spent some time working on research regarding the number of assassinations across countries. The United States was an outlier within industrialized nations. Or, if you look at the literature on the urban riots that took place in many American cities during the 1960s, you find similar questions about how this could occur in the United States while being more rare in other developed nations. In both sets of literature, social scientists debated the role of a frontier mentality, the availability of guns, levels of political conflict and inequality, among other reasons.

On a different note, given the amount of attention these mass shootings receive in the media, it isn’t a surprise that many Americans aren’t aware that crime rates have dropped or that the vast majority of public spaces are safe.

What is more important: the absolute number of crimes or the crime rate?

Chicago has received a lot of unwanted attention because of the absolute number of murders in recent years. But, a new study finds having more gun laws leads to lower gun death rates. Which is better: the absolute number or the rate?

In the dozen or so states with the most gun control-related laws, far fewer people were shot to death or killed themselves with guns than in the states with the fewest laws, the study found. Overall, states with the most laws had a 42 percent lower gun death rate than states with the least number of laws.

The results are based on an analysis of 2007-2010 gun-related homicides and suicides from the federal Centers for Disease Control and Prevention. The researchers also used data on gun control measures in all 50 states compiled by the Brady Center to Prevent Gun Violence, a well-known gun control advocacy group. They compared states by dividing them into four equal-sized groups according to the number of gun laws.

The results were published online Wednesday in the medical journal JAMA Internal Medicine.

More than 30,000 people nationwide die from guns every year nationwide, and there’s evidence that gun-related violent crime rates have increased since 2008, a journal editorial noted.

Even this first quoted paragraph conflates two different measures: the absolute number of gun deaths versus gun death rates. What does the public care most about? Rates make more sense from a comparative point of view as they reduce the differences in population. Of course Chicago would have more murders and crimes than other cities with smaller populations – after all, it is the third most populous city in the United States. Researchers are probably more inclined to use rates. But, absolute numbers tend to lead to more scintillating stories. The media can focus on milestone numbers, 400, 500, 600 murders, as well as consistently report on percentage differences as the months go by. Rates are not complicated to understand but are not as simple as absolute numbers.

I can’t help but think that a little more statistical literacy could be beneficial here. If the public and the media heard about and knew how to interpret rates, perhaps the conversation would be different.

Does demolishing buildings in Chicago actually reduce crime rates?

Chicago has pursued a policy of tearing down vacant buildings to help reduce crime but one expert doesn’t think it is making much of a difference:

Today, the city of Chicago demolished its “200th dangerous building” since July 12, according to the office of Mayor Rahm Emanuel. The mayor stated in a press release that demolitions are “preventing criminal activity in our neighborhoods.”

Is this true? “We’ve been knocking down houses since the 1930’s and it’s not clear if this has a significant effect on crime rates,” says Bradford Hunt, a sociology professor at Roosevelt University who studies Chicago housing issues…

The city murder rate has since declined, even still the number of homicides this year has surpassed 2011’s 435 total murders. Last year’s murder rate was the city’s lowest since 1965.

Chicago has traditionally been “more aggressive in doing tear downs than other cities,” Hunt says, citing Detroit as an example of a city that does not allocate crime resources to building demolitions.

In the late 1990’s, crime went down in Chicago during a spree of building teardowns, including public housing projects. But Hunt notes that the ebbing of the crack cocaine epidemic was the main cause for the 90s crime drop. Teardowns and subsequent displacement of residents have not been clearly linked to either an increase or decrease in crime.

Emanuel’s demolitions are concentrated in a few South Side and West Side police districts with high crime rates. DOB spokeswoman Susan Masell says her department works with the police department to pick buildings for demolition, looking at edifices that get a lot of 911 or 311 calls and are “structurally compromised.”

Knowing Chicago’s past regarding demolishing public housing (such as Cabrini-Green as I wrote about here and here), the continued lengthy wait lists for public housing, how the sites for public housing were chosen in the first place (generally located in already-downtrodden areas), and the shortage of affordable housing in Chicago, I suspect this is more to this story. Getting rid of these buildings might be reducing the potential for crime but it also helps clear out unsightly buildings that have little potential for redevelopment. Such buildings might take a long time to rehab or remove otherwise but suggesting they are part of a crime problem makes them an easier target.

If knocking down such buildings is so effective for fighting crime, why aren’t more cities pursuing this option?

Reminder after murder in Naperville: the suburb has the lowest crime rates of a city its size in Illinois

In the aftermath of a murder Friday night in Naperville, I wanted to issue a reminder about crime in Naperville before anyone jumps to any conclusions about violence in the suburb. Naperville is a safe place:

Naperville is by far the safest city of its size in Illinois.

The 2010 crime statistics released by the FBI Monday show that the level of crime in Naperville is far lower than is typical for Illinois’ largest cities.

For every 10,000 residents in the city, there were about 151 property crimes in Naperville, compared to 203 in Elgin and 216 in Aurora…

Rockford and Springfield reported by far the highest crime rates among the state’s largest towns. For every 10,000 Naperville residents, 9 violent crimes were reported. Elgin (33), Aurora (36) and Joliet (36) had the next best rates.

Violent crime is rare in Naperville although not unheard of. The city likes to trumpet the low crime rate. Notice how it is part of the one paragraph lead-in to the “Welcome to Naperville” video on the city’s website:

Located 28 miles west of Chicago, Naperville, Ill., is home to approximately 145,000 people. This vibrant, thriving city consistently ranks as a top community in the nation in which to live, raise children and retire. The city is home to acclaimed public and parochial schools, the best public library system in the country, an array of healthcare options and an exceptionally low crime rate. Naperville has ready access to a variety of public transportation, housing and employment options. The city’s diversified employer base features high technology firms, retailers and factories, as well as small and home-based businesses. Residents also enjoy world-class parks, diverse worship options, the opportunity to serve on several city boards and commissions, a thriving downtown shopping and dining area, a renowned living history museum known as Naper Settlement and an active civic community.

Not just a “low crime rate” but an “exceptionally low crime rate.” This pitch is made by many people beyond City Hall.

Still, a well-regarded suburb like Naperville must always be wary of perceptions. Murders in your downtown entertainment district are not the kind of news that you want. Even if crime rates are low, perceptions can change quickly and crime is one of those factors that pushes suburbanites into other communities. See this commentary from one of the Naperville high schools:

As the population rises within Naperville so do the crime rates. Naperville is known as one of the safest cities to live and raise a family in. The town claims to have a protected and secure profile, though lately there have been signs of increasing crime rates.

Naperville police have found that burglaries rose nearly thirty percent since last year while robberies climbed nearly thirty-five percent. Although property crime rates are on the rise, violent crime has decreased from the past few years.  A few months ago, senior Stephy Drago had a few friends over at night. There was about eight cars lined up in front of the house and two of the cars were broken into. A paycheck and an IPod were stolen from one car and money from the other…

Even though property crime continues to expand, recently the Naperville Police Department has let go of six police officers in late November due to a budget deficit. Hundreds of residents protested through Downtown Naperville to the outside of City Hall objecting the layoffs of these officers…

Still, proper precautions should be taken such as hiding important valuables if left in a car or locking a garage door at night.

Even though the article says Naperville has low crime rates, the perception is that crime is always just lurking around the corner. Without the “right” number of police, the safety of the town could quickly disappear. Since Naperville is such a large suburb, I wonder if it is easier for people to make the association between crime rates and the big city, making Naperville into a different kind of place. Perhaps this all says more about how Americans think about crime in general: even in the nicest places, the perceived risk of crime is up.

We shall see what happens: I assume the city will go out of its way to assure residents that this downtown incident is an isolated one and not in the character of the community. On the other hand, residents and others might start to wonder if this sort of news will become “normal.” Managing these perceptions and expectations will be important as Naperville moves forward.

Ban on lead the cause of drop in crime?

Here is a quick overview about how the reduction of lead exposure in society could have contributed to the recent decline in crime rates:

One of the most fascinating questions in American sociology, political science, and public policy is the substantial decline in violent crime in America has been falling for two decades after a near-peak in 1991; the homicide rate hit a 50-year low last year despite the recession. There are a lot of interesting theories, none that (as far as I’ve read) is considered dominant. In November, Llewellyn Hinks-Jones wrote a compelling piece for the Atlantic about crime rates and the declining price of cocaine; there’s the evergreen broken-windows theory; Steven Levitt’s abortion theory (PDF); increasing incarceration rates; the destruction of massive public-housing complexes; improved trauma care; and many more. I was reminded of another one when reading up on public housing yesterday, thanks to a brief aside in Beryl Satter’s masterful Family Properties (emphasis mine):

The “peril to life and safety of the inhabitants” of slum buildings was often of a gruesome sort. Residents were injured on poorly lit stairways or ones with broken banisters. They were knocked out by falling plaster. They were scalded by the escaping steam of malfunctioning radiators. They perished in fires in buildings where fire escapes had collapsed from neglect. Their infants’ limbs were gnawed by rats. Each year approximately twenty-five children died from eating lead-filled paint chips. Others survived lead poisoning but were left mentally disabled.

Satter’s numbers come from a Chicago Daily News report from 1963. To put that in context, between 16 and 46 young Chicagoans died from accidents each year between 2002 and 2006, the leading cause of death in the 1-14 age group. In a 1962 Trib report, a board of health poison control pilot study found 35 deaths from 1959 to 1961: “Most of the victims were from 1 to 5 years old and came from rundown slum area buildings….” 465 cases were treated at County Hospital in those two years, and another 65 suffered severe brain damage…

That’s correlation, but what about cause? The great young science writer Jonah Lehrer explains the believed chain of causation from lead poisoning to violence (emphasis mine):

Here, for instance, is a recent PLOS study from the Cincinnati Lead Study, in which the blood lead level of babies born in poor areas of Cincinnati were repeatedly measured between 1979 and 1984. Twenty years later, the researchers tracked down these subjects and put them in MRI machines, allowing them to measure the brain volume of participants. The researchers found that exposure to lead as a child was linked with a significant loss of brain volume in adulthood, particularly in men. Furthermore, there was a “dose-response” effect, in which the greatest brain volume loss was seen in participants with the greatest lead exposure. What’s especially tragic is that the loss of volume was concentrated in the prefrontal cortex, a part of the brain closely associated with executive function and impulse control.

Several things come to mind:

1. Perhaps we simply need more scientific studies in order to sort this out yet a one cause answer to the drop in crime may be really difficult to find. Human behavior within a social context is complex.

2. I wonder if this hints at an already existing and likely to grow set of studies that discuss how everyday substances negatively affect us.

3. The person who is able to conclusively/definitively find the causes in the drop in crime will be either heralded, attacked from all sides, and perhaps both.

Perceptions of crime even as the top 15 most common causes of death no longer includes homicide

I’ve noted before (see here and here) that perceptions of crime do not match the actual falling numbers. Here is more good news on the crime front: homicide has dropped off the list of the United State’s top 15 causes of death.

For the first time in almost half a century, homicide has fallen off the list of the nation’s top 15 causes of death, bumped by a lung illness that often develops in elderly people who have choked on their food.

The 2010 list, released by the government Wednesday, reflects at least two major trends: Murders are down, and deaths from certain diseases are on the rise as the population ages, health authorities said…

This is the first time since 1965 that homicide failed to make the list, according to the Centers for Disease Control and Prevention…

Murders have been declining nationally since 2006, according to FBI statistics. Falling homicide rates have been celebrated in several major cities, including New York City, Detroit and Washington.

To play a contrarian for a moment, perhaps things still aren’t great: there are still a lot of murders happening (there were still just over 16,000 in 2010 and homicide is still #16 on the list); perhaps the drop homicide from this list is more of a function of other diseases claiming more lives; and perhaps we wouldn’t usually think of murder as being a top killer (it is far away from the figures for heart disease and malignant neoplasms).

At the same time, this is good news as the number of murders dropped. Yet, Americans might perceive that they are more at risk from violent attacks than some of the leading causes of death. While the media might report on the drop in violent crime, the overall story still seems to be that crime happens frequently and could happen to you.

h/t Instapundit