2019

Mathematics ties media coverage of gun control to upticks in gun purchases


Coverage of shootings? Not so much

paper origami gun
Photo credit: NYU Tandon

For the first time, researchers have shown a causal link between print news media coverage of U.S. gun control policy in the wake of mass shooting events and increases in firearm acquisition, particularly in states with the least restrictive gun laws.

The results of a study led by researchers at NYU Tandon School of Engineering, in collaboration with faculty at the UCLA Fielding School of Public Health and Northeastern University, are rooted in a data-driven approach that reveals causal relationships, rather than mere correlations. It is the first study to quantify the influence of news media stories on firearm prevalence.

Media Coverage and Firearm Acquisition in the Aftermath of a Mass Shooting” was published today in Nature Human Behaviour.

Increases in firearm purchases following mass shootings are well-observed phenomena, likely driven by concerns that these events could lead to more restrictive gun controls. Lead author Maurizio Porfiri, NYU Tandon professor of mechanical and aerospace engineering, noted that this is the first study to empirically examine — and confirm — the link between news stories specifically about gun policy and increased acquisition of firearms. However, in one surprising finding, the analysis revealed no causal link between an actual mass shooting and gun purchases. Previous studies had noted a correlation between the two.

The latest study quantified influences among the three variables: mass shooting events, media coverage of gun control policy and regulations, and firearm acquisition. Researchers analyzed 69 mass shootings in the United States between January 1999 and December 2017, gathering data on the number of firearm background checks per month (a proxy measure for gun purchases), along with all print news coverage of firearm control policies that appeared in The New York Times and The Washington Post during that same period — more than 9,700 documents.

The increases in firearm background checks were most pronounced in states with the least restrictive gun control policies – including Alabama, Arkansas, Florida, Idaho, Kansas, Ohio, and Oregon – and less dramatic in states with stronger restrictions on gun ownership. The team found no significant links between other variables.

“This study provides the critical insight that media coverage appears to mediate the increase in firearm acquisition following mass shootings,” Porfiri said.

“The public health impact of firearm-related physical injury has dramatically increased over recent years and is now a leading cause of death,” said James A. Macinko, a co-author of the study and professor of health policy and management and community health sciences at the UCLA Fielding School of Public Health. “Our study suggests the need for dialogue around how mass shooting events are discussed by the press, in order to find ways to mitigate unintended consequences.”

The team employed a mathematical construct known as entropy transfer, which can establish causal links between multiple variables by examining the degree to which one variable influences another. In these analyses, influence is defined as an improved ability to make predictions about the future status of a variable (in this case, background checks) based on present knowledge of another variable (media stories about gun control policy). 

To further test the validity of the causal link, researchers also searched for influential relationships between mass shootings, background checks, and media coverage of gun-related topics that excluded discussion of gun control policies or regulations. The only link discovered was obvious: a causal link between mass shootings and media coverage of those events. The team also probed potential causal links between firearm background checks and media coverage of unemployment, which has been linked to higher rates of violent crime and could theoretically prompt heightened interest in acquiring firearms for self-defense. None was found.

"The results establish the first step toward our aim of creating a mathematical model of the firearm ecosystem in the United States that explains the relationships among key events," said co-author Rifat Sipahi, a professor of mechanical and industrial engineering at Northeastern University. “Moving forward, one key aspect of such a model will be to understand how subsequent events unfold and how the presence of time delays between them influence the fate of the ecosystem.”

Co-author Shinnosuke Nakayama, a postdoctoral fellow in Porfiri’s laboratory, added: “As an ecologist, I see gun violence in the U.S. as complex ecological processes consisting of multiple agents interacting with each other and the environment. By identifying keystone agents and their ecological functions through rigorous statistics, we will be able to provide tools and transparent guidance for policy."

Raghu Ram Sattanapalle, a doctoral student in Porfiri’s Dynamical Systems Laboratory, is also part of the research team. 

"At the heart of NYU Tandon is a desire to develop technologies and knowledge that make the world safer, healthier, and more sustainable,” said NYU Tandon Dean Jelena Kovačević. "This research embodies that goal, revealing new and important insights into one of the drivers behind the growth in the number of firearms in the United States. I congratulate Professor Porfiri and his collaborators on a thought-provoking paper that stands to have significant societal impact.”

The researchers acknowledge several limitations to the study, including the small number of media outlets analyzed. Additionally, background checks are not a direct measure of gun purchases, although they are the closest proxy measure due to the lack of a nationwide gun registry. The study accounted for neither the number of people killed per mass shooting nor the circumstances under which the event took place – elements that can influence media coverage.

“Media Coverage and Firearm Acquisition in the Aftermath of a Mass Shooting” is available at http://dx.doi.org/10.1038/s41562-019-0636-0.


The UCLA Fielding School of Public Health, founded in 1961, is dedicated to enhancing the public's health by conducting innovative research, training future leaders and health professionals from diverse backgrounds, translating research into policy and practice, and serving our local communities and the communities of the nation and the world. The school has 650 students from more than 35 nations engaged in carrying out the vision of building healthy futures in greater Los Angeles, California, the nation and the world.

Faculty Referenced by this Article

James Macinko
James Macinko

Professor of Community Health Sciences & Health Policy and Management, and Associate Dean for Research

Community Health Sciences Health Policy and Management
Read Faculty Profile
Marjorie Kagawa-Singer
Marjorie Kagawa-Singer
Community Health Sciences
Read Faculty Profile
Patricia Ganz
Patricia Ganz
Health Policy and Management
Read Faculty Profile
Dr. Stephanie Taylor
Stephanie L. Taylor

Nationally recognized health services researcher and sociomedical scientist with 25+ years' experience in effectiveness and implementation research.

Health Policy and Management
Read Faculty Profile
Dr. Yvonne Flores
Yvonne Flores
Health Policy and Management
Read Faculty Profile
Dr. Samuel Stratton
Samuel Stratton
Community Health Sciences
Read Faculty Profile
Dr. Gilbert Gee
Gilbert C. Gee
Community Health Sciences
Read Faculty Profile
Jack Needleman
Jack Needleman
Health Policy and Management
Read Faculty Profile
glik, deborah
Deborah Glik
Community Health Sciences
Read Faculty Profile
Courtney Thomas Tobin headshot.png
Courtney S. Thomas Tobin
Community Health Sciences
Read Faculty Profile
Clifford Ko
Clifford Ko
Health Policy and Management
Read Faculty Profile
Dr. May Sudhinaraset
May Sudhinaraset
Community Health Sciences
Read Faculty Profile
Dr. Joann Elmore
Joann G. Elmore
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Sheba George
Community Health Sciences
Read Faculty Profile
Image of Dr. Verissimo in the Sculpture Garden
Angie Otiniano Verissimo
Community Health Sciences
Read Faculty Profile
David Eisenman
David Eisenman
Community Health Sciences
Read Faculty Profile
Dr. Michael Goldstein
Michael Goldstein
Community Health Sciences
Read Faculty Profile
Paul Chung
Paul Chung
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Kimberley Shoaf
Community Health Sciences
Read Faculty Profile
Dena Herman
Dena Herman
Community Health Sciences
Read Faculty Profile
Burt Cowgill
Burt Cowgill
Health Policy and Management
Read Faculty Profile
Vickie Mays
Vickie Mays
Health Policy and Management
Read Faculty Profile
Dr. Kristen Choi
Kristen Choi
Health Policy and Management
Read Faculty Profile
Jennifer A. Wagman
Jennifer A. Wagman
Community Health Sciences
Read Faculty Profile
Roshan Bastani Headshot
Roshan Bastani
Health Policy and Management
Read Faculty Profile
Dr. Hiram Beltrán-Sánchez
Hiram Beltrán-Sánchez
Community Health Sciences
Read Faculty Profile
Dr. Randall Kuhn
Randall Kuhn
Community Health Sciences
Read Faculty Profile
Isomi Miake-Lye
Isomi Miake-Lye
Health Policy and Management
Read Faculty Profile
Galper, Michael
Michael Galper
Health Policy and Management
Read Faculty Profile
Robert Kaplan
Robert Kaplan
Health Policy and Management
Read Faculty Profile
Vilsa Eliana Curto
Vilsa Eliana Curto
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Jose J. Escarce
Health Policy and Management
Read Faculty Profile
Yusuke Tsugawa
Yusuke Tsugawa
Health Policy and Management
Read Faculty Profile
Sarah Blenner
Sarah Blenner

Director of Field Studies and Applied Professional Training

Community Health Sciences
Read Faculty Profile
Dr. Beth Glenn
Beth Glenn
Health Policy and Management
Read Faculty Profile
Jody Heymann
Jody Heymann
Epidemiology Health Policy and Management
Read Faculty Profile
Dr. John Lu
Z. John Lu
Health Policy and Management
Read Faculty Profile
Dr. Michael Prelip
Michael Prelip
Community Health Sciences
Read Faculty Profile
Charlotte Neumann
Charlotte G. Neumann
Community Health Sciences
Read Faculty Profile
Emily Abel
Emily Abel
Health Policy and Management
Read Faculty Profile
Laura Erskine
Laura Erskine
Health Policy and Management
Read Faculty Profile
Moira Inkelas
Moira Inkelas
Health Policy and Management
Read Faculty Profile
Warren Scott Comulada
Warren Scott Comulada
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Brennan Spiegel
Health Policy and Management
Read Faculty Profile
Kimberly Gregory
Kimberly Gregory
Community Health Sciences
Read Faculty Profile
Dr. Jennifer Wortham
Jennifer Wortham
Health Policy and Management
Read Faculty Profile
Dr. Judith M. Siegel
Judith M. Siegel
Community Health Sciences
Read Faculty Profile
Faculty/staff profile placeholder image
Lori Pelliccioni
Health Policy and Management
Read Faculty Profile
Dr. Risha Gidwani
Risha Gidwani
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Julie A. Elginer

EMPH Academic Program Director with expertise in healthcare marketing, finance, and reproductive health policy, teaching in the EMPH, MPH, MHA program

Health Policy and Management
Read Faculty Profile
Dr. Dana Rose Garfin
Dana Rose Garfin
Community Health Sciences
Read Faculty Profile
Comanor, Bill
William Comanor
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
David Hayes-Bautista
Health Policy and Management
Read Faculty Profile
Balgrosky headshot
Jean Balgrosky
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Arlene Fink
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Wendelin Slusser
Community Health Sciences
Read Faculty Profile
Bo-Kyung Elizabeth Kim headshot.png
Bo-Kyung Elizabeth Kim
Community Health Sciences
Read Faculty Profile
Dr. Elizabeth (Becky) Yano
Elizabeth (Becky) Yano
Health Policy and Management
Read Faculty Profile
Jeanne Miranda
Jeanne Miranda
Health Policy and Management
Read Faculty Profile
Dr. Dylan Roby
Dylan Roby
Health Policy and Management
Read Faculty Profile
Ilan H. Meyer
Ilan H. Meyer
Community Health Sciences
Read Faculty Profile
Rosenstock
Linda Rosenstock
Environmental Health Sciences Health Policy and Management
Read Faculty Profile
Corrina Moucheraud
Corrina Moucheraud
Health Policy and Management
Read Faculty Profile
Dr. Kenneth Wells
Kenneth Wells
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Alan Tomines
Health Policy and Management
Read Faculty Profile
Dr. Anne Pebley
Anne Pebley
Community Health Sciences
Read Faculty Profile
Olivia Jung
Olivia Jung
Health Policy and Management
Read Faculty Profile
May Wang headshot
May C. Wang
Community Health Sciences
Read Faculty Profile
Faculty/staff profile placeholder image
Emmeline Chuang
Health Policy and Management
Read Faculty Profile
Diana Hilberman
Diana Hilberman
Health Policy and Management
Read Faculty Profile
Freund, Deborah
Deborah Anne Freund
Health Policy and Management
Read Faculty Profile
Philip Massey headshot
Philip Massey
Community Health Sciences
Read Faculty Profile
Dr. Lillian Gelberg
Lillian Gelberg
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Annette Maxwell
Health Policy and Management
Read Faculty Profile
Image of Dr. Susan Ettner
Susan Ettner
Health Policy and Management
Read Faculty Profile
Cathy Lang
Cathy Lang

Assistant Dean for Research & Adjunct Associate Professor of Community Health Sciences

Community Health Sciences
Read Faculty Profile
Avram Kaplan
Avram Kaplan
Health Policy and Management
Read Faculty Profile
Dr. William McCarthy
William J. McCarthy
Health Policy and Management
Read Faculty Profile
Gordon headshot
Thomas D. Gordon
Health Policy and Management
Read Faculty Profile
Sangeeta Ahluwalia
Sangeeta Ahluwalia
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Thomas Priselac
Health Policy and Management
Read Faculty Profile
Dr. Shira Shafir
Shira Shafir
Community Health Sciences Epidemiology
Read Faculty Profile
Virginia C. Li
Virginia C. Li
Community Health Sciences
Read Faculty Profile
Gerald Kominski
Gerald Kominski
Health Policy and Management
Read Faculty Profile
Dr. Naomi Zewde
Naomi Zewde
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Ondine S. von Ehrenstein
Community Health Sciences Epidemiology
Read Faculty Profile
Michael Ong
Michael Ong
Health Policy and Management
Read Faculty Profile
Leah Vriesman
Leah Vriesman
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Mark Litwin
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Dawn Upchurch
Community Health Sciences
Read Faculty Profile
Robert Kim-Farley
Robert J. Kim-Farley

Robert J. Kim-Farley, MD, MPH, is a Professor-in-Residence with joint appointments in the Departments of Epidemiology and Community Health Sciences

Community Health Sciences Epidemiology
Read Faculty Profile
Dana Hunnes
Dana Hunnes
Community Health Sciences
Read Faculty Profile
Michelle Keller
Michelle S. Keller

Dr. Michelle S. Keller is a health services researcher whose research focuses on the use and prescribing of high-risk medications.

Health Policy and Management
Read Faculty Profile
Dr. Samuel Sessions
Samuel Sessions
Health Policy and Management
Read Faculty Profile
Dr. Paul Fu, Jr.
Paul Fu, Jr.
Health Policy and Management
Read Faculty Profile
Dr. Alina Dorian
Alina Dorian
Community Health Sciences
Read Faculty Profile
Faculty/staff profile placeholder image
Ron Andersen

Dr. Ron Andersen is the Wasserman Professor Emeritus in the UCLA Departments of Health Policy and Management.

Health Policy and Management
Read Faculty Profile
Aronberg, Sandra
Sandra Aronberg
Health Policy and Management
Read Faculty Profile
Dr. Chandra Ford
Chandra Ford
Community Health Sciences
Read Faculty Profile
silhoette
Ty Robbins
Health Policy and Management
Read Faculty Profile
Dr. Ninez Ponce
Ninez Ponce
Health Policy and Management
Read Faculty Profile
Dr. Aria Fallah
Aria Fallah
Health Policy and Management
Read Faculty Profile
Ron D. Hays
Ron D. Hays
Health Policy and Management
Read Faculty Profile
halbert, ronald
Ronald Halbert
Community Health Sciences
Read Faculty Profile
Dr. Jonathan Fielding
Jonathan Fielding
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Natalie Muth
Community Health Sciences
Read Faculty Profile
Dr. Michael Rodriguez
Michael Rodriguez
Community Health Sciences
Read Faculty Profile
Kadiyala, Srikanth
Srikanth Kadiyala
Health Policy and Management
Read Faculty Profile
Dr. Daniel Eisenberg
Daniel Eisenberg
Health Policy and Management
Read Faculty Profile
Dr. Thomas Rice
Thomas Rice
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Barbara Berman
Health Policy and Management
Read Faculty Profile
Dr. Xi Zhu
Xi Zhu
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Robert Brook
Health Policy and Management
Read Faculty Profile
Dr. Jessica Gipson
Jessica Gipson
Community Health Sciences
Read Faculty Profile
Faculty/staff profile placeholder image
Neal Halfon
Health Policy and Management
Read Faculty Profile
Dr. Anthony Schiff
Anthony Hunter Schiff
Health Policy and Management
Read Faculty Profile
Dr. Alice Kuo
Alice Kuo
Health Policy and Management
Read Faculty Profile
Nadereh Pourat
Nadereh Pourat
Health Policy and Management
Read Faculty Profile
Mangione, C
Carol Mangione
Health Policy and Management
Read Faculty Profile
Dr. Elizabeth Yzquierdo
Elizabeth Yzquierdo
Community Health Sciences
Read Faculty Profile
Paula Tavrow
Paula Tavrow
Community Health Sciences
Read Faculty Profile
Dr. Felicia Hodge
Felicia Hodge
Health Policy and Management
Read Faculty Profile
Dr. Donald Morisky
Donald E. Morisky
Community Health Sciences
Read Faculty Profile
Dr. Elizabeth D'Amico
Elizabeth D’Amico
Community Health Sciences
Read Faculty Profile
Dr. Frederick Zimmerman
Frederick Zimmerman
Health Policy and Management
Read Faculty Profile
Dr. Arturo Vargas Bustamante
Arturo Vargas Bustamante
Health Policy and Management
Read Faculty Profile
Faculty/staff profile placeholder image
Steven Teutsch
Health Policy and Management
Read Faculty Profile
Davidson - headshop
Pamela Davidson
Health Policy and Management
Read Faculty Profile