The latest school shooting in Florida’s Marjory Stoneman Douglas High has brought new attention to Australia’s 22-year-old national gun control laws and to the latest study of the long-term effect of those laws by two researchers at the University of Pennsylvania.

Benjamin Ukert, PhD, and Elena Andreyeva, PhD, postdoctoral researchers at both the Wharton School and the Perelman School of Medicine’s Injury Science Center, also have a second Australia gun-related study currently in journal review. Both works are focused on what happened after Australia enacted one of the world’s strictest set of gun laws.

In 1996, just twelve days after an AR-15 wielding gunman killed 35 tourists and shopkeepers at the Port Arthur historical site, the federal government of Australia announced its intention to enact stringent gun control laws and those measures were soon ratified by all six of the country’s states.


Studies and debate
Since then, the issue of whether or not those laws have resulted in a decrease in the annual number of gun-related deaths throughout Australia has been the subject of multiple research studies and ongoing political debate in both academic and political circles.

Ukert and Andreyeva, both Associate Fellows at Penn’s Leonard Davis Institute of Health Economics (LDI), are the authors of a paper published four months ago in the Journal of Experimental Criminology that critiques a 2016 paper by Simon Chapman of the University of Sydney’s School of Public Health.

Chapman’s work in the Journal of the American Medical Association (JAMA)—Association Between Gun Law Reforms and Intentional Firearm Deaths in Australia—documented a “more rapid decline” in firearm deaths between 1997 and 2013 compared with the rate before the 1996 tourist site mass shooting that sparked the passage of Australia’s gun bans. But Chapman concluded “it is not possible to determine whether the change in firearm deaths can be attributed to the gun law reforms.”

There was a significant decline in firearm-related deaths in the wake of the enactment of Australia’s laws as well as the total elimination of any further mass shootings.


Trends within trends
Ukert and Andreyeva, who used the same Australian Bureau of Statistics data, contend that it is possible to determine the decline in firearm deaths attributable to the Australian laws but that Chapman’s methods weren’t able to isolate that effect from within the broader declining trend of firearm deaths during the period. They suggest earlier studies used similarly inadequate methodology in their attempts to quantify the effect of Australia’s gun laws.

The Penn researchers’ paper concluded that “policymakers can rely only on select aspects of previous studies that show statistically significant impacts on cause-specific mortality and that future studies should better account for potential times series non-stationarity and perform some of the robustness checks” their own work demonstrates.

“There was,” said Ukert in an interview at LDI, “a significant decline in firearm-related deaths in the wake of the enactment of Australia’s laws as well as the total elimination of any further mass shootings.”


‘A methodology issue’
“This is a methodology issue,” Ukert continued. “Over the period in question, societies elsewhere, including Australia, generally became safer and experienced a downward trend in gun-related homicides. So the issue was how do we disentangle the effect of Australia’s intervention to exclude the effect of the broader downward trend. A lot of studies that looked at this didn’t account for that, so much of their evidence is actually part of the larger trend rather than the actual effect of the law.”

Andreyeva noted that the challenge seemed to be one of time series analysis. “We wanted to see if we could use the same data and find different results from previously published papers that had been very much cited in the literature and popular journals.”

Ukert, who is from Hamburg, Germany, and Andreyeva, who is from Syktyvkar, Russia, both earned their PhDs at Georgia State University (GSU) in Atlanta before coming to Penn. When they arrived in the U.S., both were somewhat unnerved by the widespread commercial availability of high-powered military weapons in neighborhood stores and as well as the frequent mass gun murders happening in American schools, churches and other public places.


‘It’s very different here’
“In Russia,” said Andreyeva, “owning a gun was never a thing—you had to be a member of law enforcement or a professional hunter or professional sports shooter to legally own a gun. The idea that your neighbor might have a firearm in their apartment never came up, but I learned in Atlanta that it’s very different here.”

Ukert’s own surprise at the laxity of U.S. gun laws and attitudes compared to those of his native Germany is what initially got him interested in the subject.

“In 2013 I was starting work on my PhD and there was this ongoing debate about whether gun regulations could actually be effective or not,” he said. “Australia was often cited as a real-world case where that could be studied but as I started digging through the literature on that, something seemed lacking.”

Two weeks ago, news of their study was circulated around the world in an article on Business Insider, a New York based media company that publishes editions throughout the industrialized world and feeds various web news platforms. Google Analytics indicates the Business Insider site logs more than 25 million page views a month not counting those generated by the sites it syndicates content into, including Yahoo Finance and

Ukert and Adreyeva point out that the Business Insider’s report was generally correct “but the reporter made it sound like we said there could be a definite effect in the U.S. based on laws like those in Australia. We didn’t say that.”


Gun control in three parts
“Back in 1996,” Ukert said, “Australia tackled three different potential causes of firearm homicide—one focused on banning semi-and fully-automatic weapons, a second focused on regulating the ownership of other types of guns, and the third was a government buy-back program that removed large numbers of guns from within the population, thus lowering the stock of guns available to be used for some sort of homicide.”

“But the bottom line,” Ukert continued, “is that we don’t know which parts of those three different interventions were effective or not and that might mean that implementation of one might do little or nothing, or even two out of the three wouldn’t do much but its some combination that actually matters. That all requires more study.”

Both researchers pointed out that it was not their goal to compare Australia to the U.S. or suggest that Australia’s gun control strategies are well suited for the U.S.

“The very dissimilar cultural history and opinions about gun ownership along with the fact that ownership rights are manifested in the Constitution makes the situation in the U.S. and Australia very different,” Andreyeva said. “It was good that the Business Insider reporter mentioned that Australia is an island continent and doesn’t share a border with any other country, so there are maybe less opportunities for smuggling guns into the country. That is a really large difference from the U.S. situation here in North America.”


Editors Note: This article was previously published on the Penn Leonard Davis Institute of Health Economics website. Read the original post here.