Nav: Home

UT Dallas study: Recent spikes in homicide rates don't tell whole story

January 11, 2018

Recent spikes in homicide rates across the nation have been attributed to causes ranging from civil unrest to the opioid epidemic, but new UT Dallas research published in the journal Homicide Studies found a much simpler explanation: The increases follow predictable fluctuations in rates over the past 55 years.

"If you look at the trends over time, you can often see ups and downs of that magnitude," said Dr. Andrew Wheeler, assistant professor of criminology in the School of Economic, Political and Policy Sciences.

The fact that homicide rates in most cities remain relatively stable, but with minor fluctuations from year-to-year suggests that long-term factors such as segregation and/or concentrated poverty play a more important role in the increases, said Dr. Tomislav V. Kovandzic, associate professor of criminology and co-author of the study.

"That doesn't mean we shouldn't pay attention to short-term spikes, as they may -- if not addressed -- contribute to a city's long-term homicide level," Kovandzic said. "But it does mean policymakers and journalists could be missing the forest for the trees if they insist on focusing on the here and now."

The U.S. homicide rate -- 5.3 homicides per 100,000 residents -- climbed nearly 12 percent from 2014 to 2015, one of the largest increases in decades, according to a U.S. Department of Justice report. It rose nearly 8 percent from 2015 to 2016. The numbers have generated headlines, raised concerns and led to speculation about the causes.

Trends in homicide rates are typically calculated by comparing the percentage change from one year to the next. But the UT Dallas study cautions that this method can create a distorted picture.

Researchers used a data analysis technique called funnel charts to compare homicide rates between cities with different populations, based on FBI Uniform Crime Reporting data from 1960 to 2015. They found that the increased homicide rates in many cities stayed within predicted levels based on past year-to-year changes.

Wheeler and Kovandzic used another data analysis technique -- time series fan charts -- to examine trends in each city over time. In most cities, the recent increased homicide rates were still much lower than rates in the early 1980s and 1990s. In others, high homicide rates were nothing new. For example, cities including St. Louis and Baltimore had experienced high homicide rates for decades.

In 2015, the homicide rate in Milwaukee was one of the nation's highest at 24.3 per 100,000 residents. The study found that the predicted rate for the city would likely fall between eight and 23 homicides per 100,000 residents based on rates before 2015. As a result, the increase was only slightly more than what could have been predicted based on Milwaukee's history.

The study also questions theories about homicide increases in some cities. For example, some attribute the rise in homicide rates in Chicago and Baltimore to decreases in police stops and arrests that resulted from civil rights litigation. But the authors point out that New York City, which also has experienced decreases in stops and arrests, has not seen increased homicide rates.

Understanding expected changes in homicide rates over a longer period of time can prevent the media, policymakers and the public from misinterpreting fluctuations, Wheeler said.

"We hope that this information can illustrate that homicide rates are volatile, so it's important to consider the size of a city and historic levels of homicide when analyzing homicide rates," Wheeler said. "Researchers focusing only on very recent homicide trends are likely to overestimate the effect of recent events."

University of Texas at Dallas

Related Homicide Articles:

Gender and homicide: Important trends across four decades
A comprehensive review of four decades of national homicide data show important gender differences and trends among homicide victims and offenders in the U.S., related to prevalence and the characteristics of the crimes and the men and women involved.
New study opens case on emotional stress of senior police investigators in child homicide
Child homicide can shatter families and communities. But what emotional effect does it have on detectives who might have to investigate such crimes repeatedly during their careers?
Researcher examines premature death in delinquent youth
Northwestern University researcher Linda Teplin will share data showing alarming premature mortality rates for delinquent youth at the American Association for the Advancement of Science (AAAS) annual meeting in Boston.
Homicide rates rise after introduction of 'Stand Your Ground' self-defense law
The study says this change in the law is associated with homicide rates in Florida rising by 24 percent over 2005-2014 (compared with 1999-2004).
Do juvenile murderers deserve life without parole?
The US Supreme Court answered this question in two recent decisions (Miller v.
Australia 20 years after gun reform -- no mass shootings, declining firearm deaths
Since gun law reform and the Firearms Buyback program 20 years ago, Australia has seen an accelerating decline in intentional firearm deaths and an absence of fatal mass shootings, the Journal of the American Medical Association (JAMA) reports today in a landmark study.
How US police departments can clear more homicides
Only about 65 percent of homicides in the United States are solved -- down 15 percent from the mid-1970s -- but a new study led by a Michigan State University criminologist examines how some police departments are getting it right.
Child homicide -- speaking of the unspeakable
New estimates published in PLOS Medicine suggest that homicide could be responsible for just over 1 percent of all neonatal deaths in South Africa.
Exposure to violence during pregnancy increases risk of prematurity and low birthweight
Queen Mary University of London and University of Leicester study suggests stress-induced events have negative effects on unborn children in early pregnancy.
Minorities' homicide victimization rates fall significantly compared to whites'
A new study reveals that while homicide victimization rates declined for whites, blacks, and Hispanics in the United States from 1990-2010, the drop was much more precipitous for the two minority groups.

Related Homicide Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".