On 24 March 2018, more than two million people took to the streets in the US to protest gun violence. What the solution to that problem looks like depends on who you ask. Some wish to repeal citizens’ rights to bear arms, while others want to arm even more people. Most Americans have opinions that fall somewhere in between.

But what would happen if that debate was suddenly and irrevocably put to rest – because there were no guns at all? What if all firearms in the world suddenly disappeared with no way to get them back?

Guns obviously cannot just magically vanish. But this thought experiment allows us to remove politics from the equation and rationally consider what we could gain – and lose – should we ever actually decide to have fewer guns around.

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In the US, gun homicide rates are more than 25 times higher than the combined rate of other high-income nations

The most obvious effect of such a disappearance is simple: no gun deaths. Approximately 500,000 people around the world are killed by guns each year. In terms of developed countries, the biggest losses are in the US, where citizens own 300 to 350 million guns in total. There, gun homicide rates are more than 25 times higher than the combined rate of other high-income nations.

“About 100 people in this country die every day as a result of a gunshot,” says Jeffrey Swanson, a professor of psychiatry and behavioural science at Duke University School of Medicine in North Carolina. “If you take away the guns, lots and lots of those lives will be saved.”

Ranking at the top of that list would be lives otherwise lost to suicide. Around 60% of the 175,700 US firearm deaths from 2012 to 2016 were suicides, and half of the 44,000 Americans who killed themselves in 2015 used a gun.

More than 80% of attempted suicides with a gun end in death, but most survivors of suicide attempts never go on to take their own life

More than 80% of attempted suicides with a gun end in death. “Unfortunately, the chances of survival are very low,” says criminologist and sociologist Tom Gabor, author of Confronting Gun Violence in America.

What’s more, most survivors of suicide attempts never go on to take their own life.

“Some folks are determined to die and will find another way to do it. But others are impulsive one-timers who’d go on to have very happy and productive lives,” says Ted Miller, a principal research scientist at the Pacific Institute for Research and Evaluation. “That’s especially true of a lot of kids.”

Firearm bans

Australia provides compelling real-world evidence that fewer available guns correlates with a significant reduction in deaths – by suicide, and also by gun violence. In 1996, Martin Bryant opened fire on visitors at Port Arthur Historic Site in Tasmania, killing 35 people and injuring 23. For Australians, that tragedy marked a turning point. People of all political slants supported a ban against semi-automatic shotguns and rifles. In a matter of days, new legislation was enacted. The government purchased newly banned firearms at fair market value and then destroyed them, reducing Australia’s civilian gun stockpile by 30%.

Philip Alpers, an adjunct associate professor at the Sydney School of Public Health, argues that the data shows that the impact of the gun legislation on deaths has been significant. That is the case true even if you take into account other possible explanations and pre-existing declines in suicide and homicide rates. “The result of that was the risk of dying by gunshot in Australia statistically reduced by more than 50%, and in the past 22 years has shown no sign of creeping up again,” he says.

There is no evidence that those intending to commit suicide or homicide simply moved on to another weapon – Philip Alpers

Suicide was a big part of that drop: up to 80% of gun suicides no longer happened. “Suicide went down and surprised the hell out of us,” Alpers says. “Even more so, we were delighted to discover that the displacement of lethal methods did not occur. In other words, there is no evidence that those intending to commit suicide or homicide simply moved on to another weapon.”

It wasn’t just suicides. The rate of gun homicides in Australia was also slashed by more than half following the ban. And furthermore, while critics in the US often argue that murderers would just find another way to kill their victims, that didn’t happen in Australia. Instead, non-gun homicides remained roughly the same – meaning a drop in murders overall. “Murderers simply do not choose another weapon,” Alpers says.

This likely especially applies to domestic abusers. A woman whose violent partner has access to a gun is five to eight times more likely to be killed. If guns disappeared, partners who lash out in a moment of anger are much less likely to inflict fatal damage – and are perhaps less likely to become violent at all. Though controversial, some research indicates that the mere presence of a gun makes men behave more aggressively, a phenomenon called “the weapons effect”.

Some research indicates that the mere presence of a gun makes men behave more aggressively

Should guns disappear, the US – where 50 women are shot to death by partners each month – likely would experience a similar decline in death as Australia.

The US is unexceptional in its overall level of most types of crime: it’s about average when compared to the UK, Western Europe, Japan and other developed nations.When it comes to homicides, however, the US rate is about four times higher. That’s because it’s much more likely a gun rather than another type of weapon will be used in an assault in the US, which increases the risk of death by a factor of seven.

“Think of two immature, angry, impulsive and intoxicated young men in the UK who come out of a pub and get into an argument,” Swanson says. “Someone’s going to get a black eye or bloody nose.”

“But in our country [the US],” he says, “it’s statistically more likely one of those men will have a hand gun, and you’re going to get a dead body.”

That difference boils down to what experts refer to as the ‘weapons instrumentality effect’: the fact that the weapon used has an effect on the outcome, says Robert Spitzer, a political science professor at the State University of New York College at Cortland. “There’s no weapon more efficient at killing people than a gun.”

A 2017 study revealed that firearm homicide rates are lower in US states with stricter gun laws

As in Australia, real-world evidence from the US also shows that fewer guns result in fewer deaths and injuries. A 2017 study revealed that firearm homicide rates are lower in US states with stricter gun laws, while a 2014 analysis of all inpatient minors admitted to hospitals for trauma linked tighter firearm control to greater safety for children.

Guns also make interactions with the police deadlier. While the probability of an arrest causing injuries is the same in the US, British Columbia and Western Australia, research shows that “almost no one dies during an arrest in Australia or Canada,” Miller says – even though police in all three countries carry guns.

In the US, however, nearly 1,000 citizens are annually killed by police. Of course, the reasons for officer-involved violence are complex and often involve racial bias against non-white citizens, including even among African-American police themselves. Still, many of those deaths would likely be prevented were guns not involved.

“A lot of police brutality is really just because of police who themselves are in fear that they might get shot,” Miller says. “When police must guard against a gun during every stop, interactions become more lethal.”

No more guns would likewise mean safer conditions for police, Miller adds. More than half of the people killed by police in 2016 were armed, and many were exchanging fire with officers when they were shot.

Guns were used in just 10% of terror attacks but accounted for 55% of deaths

Deadly mass attacks by domestic terrorists also would decline. A 2017 study of more than 2,800 attacks in the US, Canada, Western Europe, Australia and New Zealand revealed that guns are by far the most lethal way to kill as many people as possible – even more than explosives or vehicular strikes. Guns were used in just 10% of attacks but accounted for 55% of deaths. In the US, terrorists also prefer guns: out of 16 lethal terrorism-associated attacks since 9/11, all but two involved firearms.

“Even building basic stuff like a pipe bomb is hard,” says Risa Brooks, a professor of political science at Marquette University in Wisconsin. “By making it more difficult to get access to a lethal weapon, you’re making it harder for terrorists to engage in violence.”

Improbable peace

History shows that violence is ingrained in human nature, however, and guns are by no means a prerequisite for conflict. “Think of the Rwandan genocide,” says David Yamane, a professor of sociology at Wake Forest University in North Carolina. “There was tremendous violence, much without firearms.”

Even when we take the thought experiment to its extreme and imagine all guns disappearing off the face of the Earth, war and civil strife would continue. But rather than revert to more primitive weaponry like spears, swords or bows and arrows, modern nations would likely shift to other forms of killing, including explosives, tanks, missiles and chemical and biological weapons. (Nuclear war, however, would likely remain unappealing given its extreme destructiveness, Gabor says.)

Nations also may invent new types of weapons to fill gaps left by guns, Brooks adds, with the wealthiest, most powerful states likely being the quickest to innovate the most effective new means of killing. So while warfare between states would change, “you wouldn’t necessarily change the balance of power,” Brooks says.

The same probably would not hold true for non-state actors. In places like Somalia, Sudan and Libya, where firearms are readily available, a sudden disappearance of those weapons would reduce the capacity for militias to emerge and operate. “One thing that defines non-state actors is lack of capital-intensive equipment,” she says. “They need stuff that’s easy to get, easy to transport and easy to store and hide.”

A decline in various militias’ power may sound like a good thing. But in some cases, counter-militias are composed of fighters resisting violent, repressive governments, Brooks says.

Natural world

Should guns disappear, there also would be mixed results for animals. On the one hand, the poaching and trophy hunting of endangered species would decline greatly. On the other, control of problem animals – whether rabid raccoons, stampeding elephants, venomous snakes or charging polar bears – would become more difficult.

On farms, guns are a standard tool of the trade – Alpers

“There are plenty of legitimate reasons for firearm ownership, especially in a country like Australia that’s agricultural and has a similar frontier history to the US,” Alpers says. “On farms, they’re a standard tool of the trade.”

Guns are also integral for invasive species management, he continues. Thousands of cats, pigs, goats, possums and other harmful non-native species are shot each year to try to preserve delicate ecosystems, especially on islands. Doing away with guns would make that already-steep uphill battle all the more difficult – and less humane. Mercy killings of injured livestock and other animals likewise would be made more brutal without guns. “If you’ve got a big, sick animal, a hatchet is no substitution for a quick death with a firearm,” Alpers says.

Money matters

Guns are made for killing, but their influence extends to additional facets of life and society, all of which would change.

In terms of the economy, the US stands the most to lose if guns disappeared. The Firearms Industry Trade Association calculates that the firearms industry accounts for $20 billion (£15 billion) in direct contributions, plus another $30 billion (£20 billion) in other contributions. For the US economy, though, losing $50 billion (£35 billion) “wouldn’t even be a blip on the screen,” Spitzer says. “It’s not zero, but it’s just not very big compared to the economy as a whole.”

There would likely be a modest net economic gain if guns disappeared

In fact, there would likely be a modest net economic gain if guns disappeared. Gun death and injury-related expenses add up to direct losses of around $10.7 billion (£7 billion) per year, and more than $200 billion (£140 billion) when other factors are taken into account. “In the US, if you look at all the financial costs of gun violence, it’s not just direct medical costs and rehabilitation for people who are shot, but costs to the justice system and lost income of victims, and even quality of life costs,” Gabor says.

Indeed, while the overall impacts to the economy would be negligible, Miller points out that the less tangible gains would be significant. For one, many people would feel safer. “We’d see new generations that were not traumatised by the sound of gunfire that they could hear from their bedroom,” he says. “That could make a huge difference in the mental health of our children.”

Americans of all ages are increasingly terrified of being attacked in a public place, Gabor adds, whether at school, a movie theatre, a nightclub or on the street. Even if such events are relatively rare, “this onslaught of mass shootings tears at the social fabric,” he says. “People’s sense of security and trust in each other is eroded, causing profound social and psychological effects.”

Many would be able to breathe easier with guns no longer in the picture, but some gun owners would experience the opposite effect and feel more vulnerable without their weapons. “There are people in the defensive gun world who arm themselves against others – whether that’s larger people, people with knives or others with guns – to equalise the situation,” Yamane says. Removing guns “would definitely leave people who are potential victims of violence unable to defend themselves against stronger, more forceful attackers,” he says.

Removing guns would leave people who are potential victims of violence unable to defend themselves against stronger, more forceful attackers – David Yamane

Whether guns actually help people stay safe and defend themselves is a controversial subject. But the limited research available on this topic tends to indicate that guns have the opposite effect. A 1993 study of 1,860 homicides found that the presence of guns in a home significantly increases the risk of homicide by a family member or intimate acquaintance, for example. A 2014 meta-study likewise found that access to firearms is associated with homicide and completed suicide attempts.

So while some gun owners may lose a sense of security if guns disappeared, “the data show that’s a false sense of security,” Miller says.

Gun culture also would be something that many firearm owners would miss. But Miller points out that recreational hunters could shift from rifles to other means of killing, such as bows and arrows. The same goes for those who visit shooting ranges for fun, or who collect guns as a hobby – they simply could find a replacement activity. Though for someone for whom guns are a passion, that is unlikely to be much comfort.

“They’d get a bit of loss of enjoyment because they wanted to buy a gun more than they wanted to buy a television set or whatever,” Miller says. “But on the other hand, a lot of people would still be alive. And I think that outweighs loss of enjoyment.”

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