Gun control

Regulation of civilian firearms

With few exceptions, most countries in the world allow some form of civilian firearm ownership. A 2011 survey of 28 countries over five continents found that a major distinction between different national gun control regimes is whether civilian gun ownership is seen as a right or a privilege.

The study concluded that both the United States and Yemen were distinct from the other countries surveyed in that they viewed gun ownership as a basic right of citizenship, and therefore their gun control policies are more permissive. In the remaining countries sampled, civilian gun ownership is considered a privilege, and their corresponding gun control policies are more restrictive. For many countries that view gun ownership as a privilege, gun rights, such as those in the United States, may be seen as too permissive.

Some countries, like those in East and Southeast Asia, can be particularly strict. East Asian countries are usually more indifferent to gun control and the gun rights debate. Countries like Japan and China enact strict controls on gun ownership. Some countries in these regions impose more extreme punishments than typically imposed by most countries for the same crime; for example, illegal gun ownership in Indonesia can be punished with a maximum of 20 years in prison, life in prison, or the death penalty.

For almost all European countries, gun ownership pertains to hunting and sport, and requires licensure with backgrounds checks.

International and regional gun control

At the international and regional level, diplomatic attention has tended to focus on the cross-border illegal trade in small arms as an area of particular concern, rather than the regulation of civilian-held firearms. During the mid-1990s, however, the United Nations Economic and Social Council (ECOSOC) adopted a series of resolutions relating to the civilian ownership of small arms. These resolutions called for the exchange of data on national systems of firearm regulation and for the initiation of an international study of the issue. In July 1997, ECOSOC issued a resolution that underlined the responsibility of UN member states to competently regulate civilian ownership of small arms and urged them to ensure that their regulatory frameworks encompassed the following aspects: firearm safety and storage; penalties for the unlawful possession and misuse of firearms; a licensing system to prevent undesirable persons from owning firearms; exemption from criminal liability to promote the surrender of illegal, unsafe or unwanted guns by citizens; and a record-keeping system to track civilian firearms.

In 1997, the United Nations (UN) published a study based on member state survey data titled the United Nations International Study on Firearm Regulation, which was updated in 1999. This study was intended to initiate the establishment of a database on civilian firearm regulations which would be run by the Centre for International Crime Prevention, located in Vienna, Austria, which was to report on national systems of civilian firearm regulation every two years. These plans never reached fruition, and further UN-led efforts to establish international norms for the regulation of civilian-held firearms were stymied. Responding to pressure from the US government, any mention of the regulation of civilian ownership of small arms was removed from the draft proposals for the 2001 UN Programme of Action on Small Arms.

Although the issue is no longer part of the UN policy debate, there have been eight regional agreements since 1991, involving 110 countries, concerning aspects of civilian firearm possession. The Bamako Declaration was adopted in Bamako, Mali on 1 December 2000 by the representatives of the member states of the Organisation of African Unity (OAU). The provisions of this declaration recommend that the signatories establish the illegal possession of small arms and light weapons as a criminal offence under national law in their respective countries.

Historical context

16th century

Debates over gun control emerged in the early 16th century, particularly in response to the spread of the wheellock mechanism, which made guns smaller and easier to conceal than earlier matchlocks. In 1518, wheellock firearms were prohibited in Habsburg territories, and a similar ban followed in the Duchy of Ferrara in 1522. By the mid-16th century, similar bans had spread across much of the Italian peninsula, and some states briefly restricted the manufacture of small wheellocks.

Throughout the 16th century, many European cities enacted restrictions on carrying firearms in urban areas. Larger guns usually continued to be allowed in the countryside, especially for hunting. Rules on gun ownership gradually reverted to older patterns that limited the bearing of arms to the upper class and their servants.

The expansion of town militias during the 16th century increased routine civilian access to firearms. By mid-century, a view had developed in parts of Europe that carrying firearms for self-defense should be allowed. A Venetian official in the same period linked wider gun ownership in Brescia (a center of gun manufacturing) to a decline in homicides within the city. At the same time, an anonymous treatise from the 1570s questioned the practical value of firearms for self-defense.

17th century

In 1638, citing the "many inconveniences that arise daily from the carrying of arms", Cardinal Francesco Barberini issued a public ban prohibiting the carrying of firearms within the Papal States. The ban forbade any person, regardless of rank, from carrying arquebuses or terzaroli (short firearms), whether in cities or in the countryside, unless specifically permitted. Penalties ranged from fines for carrying long guns in the countryside to five years' galley service in towns. Short firearms were punished more severely, including confiscation of property, and in certain cases, capital punishment. Later popes, including Innocent XIII and Benedict XIV, attempted to extend the enforcement of such edicts into baronial jurisdictions, though with limited success.

2000s statistics

In more recent years, calls for gun control have grown as the number of school shootings has risen. High rates of gun mortality and injury are often cited as a primary impetus for gun control policies.

In 2007, a global supply of 875 million small arms was estimated to be in the hands of civilians, law enforcement agencies, and national armed forces. Of these firearms, 650 million, or 75%, were estimated to be held by civilians. US civilians account for 270 million of this total. A further 200 million are controlled by national military forces. Law enforcement agencies may have some 26 million small arms. Non-state armed groups have about 1.4 million firearms. Finally, gang members hold between 2 and 10 million small arms. Together, the small arms arsenals of non-state armed groups and gangs have been estimated to account for, at most, 1.4% of the global total.

United States

The United States has more guns per citizen than any other Western country. In the US, gun rights activists argue that gun laws are too restrictive or should not be altered, and gun control activists argue that gun laws are too permissive. Both camps center their arguments upon the legal and traditional interpretations of the Second Amendment to the US Constitution. Gun control measures include the Federal Assault Weapons Ban of 1994 that prohibited manufacturing certain semi-automatic firearms that were defined as assault weapons for civilian use. The act expired ten years after its effective date in 2004. Attempted gun control measures included the Assault Weapons Ban of 2013 bill, which was not passed into law.

Canada

In Canada, the Canadian Criminal Code, enacted in 1892, required individuals to have a permit to carry a pistol unless the owner had cause to fear assault or injury. Handgun registration became law in 1934, and automatic firearms registration was added in 1951, then the Criminal Law Amendment Act. In 1977, Bill C-51 required firearms acquisition certificates (FACs) to purchase any firearm.

On 1 May 2020, after deadly shootings in Nova Scotia, Prime Minister Justin Trudeau's government banned 1,500 kinds of military-style semi-automatic rifles, including the popular AR-15 and its variants. The ban was enacted via an Order In Council.

On 21 October 2022, still under the 29th Canadian Ministry with Trudeau as prime minister, Bill C-21 came into effect, aiming to address gun violence and strengthen gun control. The legislation introduced a national freeze on the sale, purchase, or transfer of handguns by individuals within Canada. It also established new "red flag" and "yellow flag" laws (similar to American red flag laws, with risk-based gun removal), allowing courts and Chief Firearms Officers (CFOs) to issue emergency weapons prohibition orders and temporarily suspend licenses, respectively. Moreover, the bill increased maximum penalties for firearms-related offenses, including gun smuggling and gun trafficking, from 10 to 14 years imprisonment. Additionally, Bill C-21 prohibited mid-velocity "replica" airguns that closely resemble real firearms and discharge projectiles at a velocity between 366 and 500 feet per second.

Australia

In Australia, gun control laws were enacted in the state of Victoria in 1988; the Opinel shooting led to a significant change in gun ownership legislation, along with the Port Arthur massacre in 1996. The National Firearms Agreement (NFA) was formed 12 days after the killing. John Howard, the prime minister at the time, said in proposing it: "We need to achieve a total prohibition on the ownership, possession, sale and importation of all automatic and semi-automatic weapons. That will be the essence of the proposal... ". The National Firearms Agreement was agreed upon on 10 May 1996.

Studies for legislature effectiveness

A 1998 review found that suicide rates generally declined after gun control laws were enacted, and concluded, "The findings support gun control measures as a strategy for reducing suicide rates." A 2016 review found that laws banning people under restraining orders due to domestic violence convictions from accessing guns were associated with "reductions in intimate partner homicide". Another 2016 review identified 130 studies regarding restrictive gun laws and found that the implementation of multiple such laws simultaneously was associated with a decrease in gun-related deaths. According to Vox, "The authors are careful to note that their findings do not conclusively prove that gun restrictions reduce gun deaths. However, they did find a compelling trend whereby new restrictions on gun purchasing and ownership tended to be followed by a decline in gun deaths."

In 2011, a UN study found, despite identifying a number of methodological problems, that: "Notwithstanding such challenges, a significant body of literature tends to suggest that firearm availability predominantly represents a risk factor rather than a protective factor for homicide. In particular, a number of quantitative studies tend towards demonstrating a firearm prevalence-homicide association."

United States

A National Research Council critical review in 2004 found that, while some strong conclusions are warranted from current research, the state of knowledge is generally poor. The scarcity of relevant data has made gun control one of the most contentious topics in American politics, and scholars remain deadlocked on a variety of issues. Notably, since 1996, when the Dickey Amendment was first inserted into the federal spending bill, the Centers for Disease Control and Prevention (CDC) has been prohibited from using its federal funding "to advocate or promote gun control", thwarting gun violence research at the agency at the time. The funding provision's author has said that this was an over-interpretation, but the amendment still had the outcome of effectively halting federally funded firearm-related research. Since the amendment, the CDC has continued to research gun violence and publish studies about it, although their funding for such research has fallen by 96% since 1996, according to Mayors Against Illegal Guns. According to a spokesman, the CDC has limited funding and has not produced any comprehensive study aimed at reducing gun violence since 2001.

In 2007, the global supply of 875 million small arms was estimated to be in the hands of civilians, law enforcement agencies, and national armed forces, of which 650 million, or 75%, were estimated to be held by civilians. US civilians accounted for 270 million of this total. Later research in 2017 showed the United States had 393 million privately-owned firearms at a per-capita rate of 120.5 per 100 residents.

Cross-sectional studies

In 1983, a cross-sectional study of all 50 US states found that the six states with the most restrictive gun laws (according to the National Rifle Association of America) had suicide rates that were lower than other states by approximately 3 in 100,000 people, and compared to states with the most permissive gun laws the rates were lower by 4 in 100,000 people.

A 2003 study published in the American Journal of Preventive Medicine looked at the restrictiveness of gun laws and suicide rates in men and women in all 50 US states and found that states with more restrictive gun laws had lower suicide rates among both sexes. In 2004, from the National Research Council, commissioned by the National Academy of sciences, it was concluded that the effect of state-level gun laws on gun-related homicides was "limited" and had no measurable effect on violent crime.

A 2005 study looked at all 50 states in the US and the District of Columbia, and found that no gun laws had a particular association with reductions in firearm homicide or suicide, but that a "shall-issue" (mandatory issue of a license when legal criteria met) concealed carry law may be associated with increased firearm homicide rates.

A 2011 study found that firearm regulation laws in the US have "a significant deterrent effect on male suicide".

A 2013 study by the American Medical Association found that, "a higher number of firearm laws in a state are associated with a lower rate of firearm fatalities in that state." Other studies comparing gun control laws in different US states include a 2014 study, which found that states requiring licensing and inspections of gun dealers tended to have lower rates of gun homicides. Another study published the same year, analyzing panel data from all 50 states, found that stricter gun laws may modestly reduce gun deaths. A study in 2015 also found that "stricter state firearm legislation is associated with lower discharge rates" for nonfatal gun injuries.

A 2016 study published in The Lancet found that, of 25 laws studied and in the time period examined (2008–2010), nine were associated with reduced firearm mortality (including both homicide and suicide), nine were associated with increased mortality, and seven had an inconclusive association. The three laws most strongly associated with reduced firearm mortality were laws requiring universal background checks, background checks for ammunition sales, and identification for guns. In an accompanying commentary, economist David Hemenway noted that this study had multiple limitations, such as not controlling for all factors that may influence gun-related deaths aside from gun control laws and the use of 29 explanatory variables in the analysis.

A study from Quinnipiac University economist Mark Guis, using a 30-year period, found a positive correlation between certain restrictions and violent crime. For example, the correlation indicated that violent crime was 19.3% higher on a state level when the federal "assault weapons" ban was in effect. It also found that states with stricter concealed carry laws had a 10% higher gun-related murder rate. Another study, published the same year, found that states with permit to purchase, registration, and/or license laws for handguns had lower overall suicide rates, as well as lower firearm suicide rates.

A 2014 study found that children living in states with stricter gun laws were safer. Similarly, a study in 2016 found that US states with lenient gun control laws had more gun-related child injury hospital admissions than states with stricter gun control laws.

A study looking specifically at suicide rates in the US found that the four handgun laws examined (waiting periods, universal background checks, gun locks, and open carrying regulations) were associated with "significantly lower firearm suicide rates and the proportion of suicides resulting from firearms". The study also found that all four of these laws (except the waiting-period law) were associated with reductions in the overall suicide rate.

A 2016 study found that US military veterans tend to commit suicide with guns more often than the general population, thereby possibly increasing state suicide rates, and that "the tendency for veterans to live in states without handgun legislation may exacerbate this phenomenon". Another study in 2016 found that stricter state gun laws in the United States reduced suicide rates.

California has exceptionally strict gun sales laws, and a 2015 study found that it also had the oldest guns recovered in crimes of any states in the US. The same study stated, "These findings suggest that more restrictive gun sales laws and gun dealer regulations do make it more difficult for criminals to acquire new guns first purchased at retail outlets." A study in 2017 showed that laws banning gun possession by people subject to intimate partner violence restraining orders, as well as requiring such people to give up any guns they have, were associated with lower intimate partner homicide rates.

Waiting period laws

A 2017 study found that suicide rates declined more in states with universal background check and mandatory waiting period laws than in states without these laws. Another 2017 study found that states without universal background check and/or waiting period laws had steeper increases in their suicide rates than did states with these laws. A third 2017 study found that "waiting period laws that delay the purchase of firearms by a few days reduce gun homicides by roughly 17%".

A 2017 study in the Economic Journal found that mandatory handgun purchase delays reduced "firearm-related suicides by between 2 and 5 percent with no statistically significant increase in non-firearm suicides", and were "not associated with statistically significant changes in homicide rates".

A study in 2021 found that firearm purchase delay laws reduced homicide; the authors suggested that it was driven by reductions in gun purchases by impulsive customers.

Findings of systematic reviews

In 2015, Daniel Webster and Garen Wintemute reviewed studies examining the effectiveness of gun laws aimed at keeping guns out of the hands of high-risk individuals in the United States. They found that some laws prohibiting gun possession by people under domestic violence restraining orders or who had been convicted of violent misdemeanors were associated with lower violence rates, as were laws establishing more procedures to check if people were prohibited from owning a gun under these laws. They also found that multiple other gun regulations intended to prevent prohibited individuals from obtaining guns, such as "rigorous permit-to-purchase" laws and "comprehensive background checks", were "negatively associated with the diversion of guns to criminals".

A 2016 systematic review found that restrictive gun licensing laws were associated with lower gun injury rates, while concealed carry laws were not significantly associated with rates of such injuries. Another systematic review found that stricter gun laws were associated with lower gun homicide rates; this association was especially strong for background check and permit-to-purchase laws.

A 2024 review by RAND Corporation of thousands of studies published between 2004 and 2023 found only 207 that met their criteria of methodological rigor, suggesting that "rigorous scientific evidence concerning the effects of many commonly discussed gun policies remains limited". Additionally, only 4 of the 18 gun policies they examined had strong supportive evidence. The policies with the strongest supporting evidence were: child access prevention laws reduce firearm assault and self-injuries, homicides, and deaths among young people; "stand-your-ground" laws increase firearm homicides; raising the minimum age requirement for the purchase of firearms reduces firearm suicide deaths among young people; and "shall-issue" concealed carry laws increase total homicides, firearm homicides, and violent crime. RAND also noted that the limitations of currently available evidence "does not mean that these policies are ineffective ... Instead, it partly reflects shortcomings in the contributions that science has made to policy debates."

Studies of individual laws

Other studies have examined trends in firearm-related deaths before and after gun control laws are either enacted or repealed. A 2004 study in the Journal of the American Medical Association found evidence that child access prevention laws were "associated with a modest reduction in suicide rates among youth aged 14 to 17 years".

Two 2015 studies found that the permit-to-purchase law passed in Connecticut in 1995 was associated with a reduction in firearm suicides and homicides. One of these studies also found that the repeal of Missouri's permit-to-purchase law was associated with "a 16.1% increase in firearm suicide rates", and a 2014 study by the same research team found that the repeal of this law was associated with a 16% increase in homicide rates.

A 2000 study designed to assess the effectiveness of the Brady Handgun Violence Prevention Act found that the law was not associated with reductions in overall homicide or suicide rates, but that it was associated with a reduction in the firearm suicide rate among individuals aged 55 or older.

A 1991 study looked at Washington, D.C.'s Firearms Control Regulations Act of 1975, which banned its residents from owning all guns except certain shotguns and sporting rifles, which were also required to be stored unloaded, disassembled, or with a trigger lock in their owners' homes. The study found that the law's enactment was associated with "a prompt decline in homicides and suicides by firearms in the District of Columbia". A 1996 study reanalyzed this data and reached a significantly different conclusion as to the effectiveness of this law.

Other studies and debate

In 1993, Kleck and Patterson analyzed the impact of 18 major types of gun control laws on every major type of gun-involved crime or violence (including suicide) in 170 US cities, and found that gun laws generally had no significant effect on violent crime rates or suicide rates. Similarly, a 1997 study found that gun control laws had only a small influence on the rate of gun deaths in US states compared to socioeconomic variables like poverty and unemployment.

Philosophy professor Michael Huemer argued that gun control may be morally wrong, even if its outcomes would be positive, because individuals have a prima facie right to own a gun for self-defense and recreation.

A 2007 article published by the Journal of Injury Prevention states that approximately 60% of firearms used to commit violent crime can be traced to 1% of licensed dealers. This finding indicates that, although gun laws effectively regulate approximately 99% of purchases made from licensed dealers, a majority of gun-related violent crimes are perpetrated using guns that were purchased in violation of regulations. The Journal of Injury Prevention article advocates for increased monitoring of gun vendors in tandem with the optimization of gun sale regulation as a means to decrease violent crime perpetrated with a firearm.

In 2009, the Public Health Law Research program, an independent organization, published several evidence briefs summarizing the research that assesses the effects of a specific law or policy on public health, particularly as concerns the effectiveness of various laws related to gun safety. Among their findings:

• There is not enough evidence to establish the effectiveness of "shall-issue" laws, as distinct from "may-issue" laws, as a public health intervention to reduce violent crime.
• There is insufficient evidence to determine the effectiveness of waiting period laws as public health interventions aimed at preventing gun-related violence and suicide.
• Although child access prevention laws may represent a promising intervention for reducing gun-related morbidity and mortality among children, there is currently insufficient evidence to validate their effectiveness as a public health intervention aimed at reducing gun-related harms.
• There is insufficient evidence to establish the effectiveness of such bans as public health interventions aimed at reducing gun-related harms.
• There is insufficient evidence to validate the effectiveness of firearm licensing and registration requirements as legal interventions aimed to reduce firearm related harms.

The RAND Corporation conducted a study that demonstrates that background checks may decrease suicides and violent crime; child-access prevention laws may decrease the number of suicides and unintentional injuries and deaths; minimum age requirements may decrease suicides; and prohibitions associated with mental illness may decrease suicides and violent crimes. Additionally, concealed carry laws may increase violent crimes and suicides, while "stand your ground" laws may increase violent crime. Waiting periods and background checks were found to have a moderate effect on lowering violent crime; meanwhile, assault weapons bans, gun registration, and magazine bans were found to have an inconclusive effect on violent crime.

An August 2019 article in Business Insider entitled "Gun control really works" looked at a dozen studies by the CDC, The Journal of the American Medical Association, Rand Corporation, the journal Preventive Medicine, Everytown for Gun Safety, Johns Hopkins University, and others. They concluded that mirroring the firearms regulations in Switzerland such as banning the sale of new assault weapons, denying concealed carry licenses to some individuals, and prohibiting firearm sales to people convicted of multiple alcohol-related offenses will decrease gun-related deaths and injuries.

Canada

With respect to the Criminal Law Amendment Act, a gun control law passed in Canada in 1977. Some studies have found that it was ineffective at reducing homicide or robbery rates, with one study finding that the law may have actually increased robberies involving firearms.

A 1993 study found that, after the 1977 law was passed, gun suicides decreased significantly, as did the proportion of suicides committed in the country with guns. A 2003 study found that the law "may have had an impact on suicide rates, even after controls for social variables," while a 2001 study by the same research team concluded that the law "may have had an impact on homicide rates, at least for older victims."

A 1994 study found that, after this law came into force in 1978, suicide rates decreased over time in the province of Ontario, and that there was no evidence of method substitution. The same study found that, "These decreases may be only partly due to the legislation."

In 1991, Canada implemented the gun control law Bill C-17. According to a 2004 study, after this law was passed, firearm-related suicides and homicides, as well as the percentage of suicides involving firearms, declined significantly. A 2010 study found that after this law was passed, firearm suicides declined in the province of Quebec among men, but acknowledged that this may not represent a causal relationship. In 1992, Canada promulgated the Canadian Firearms Act, which aimed at ensuring that guns were stored safely.

A 2004 study found that, while firearm suicide rates declined in the Quebec region of Abitibi-Témiscamingue after the law was passed, overall suicide rates did not. A study in 2005 also found that overall suicide rates did not change after passage of Bill C-17.

A 2008 study reached similar conclusions with regard to the entire Quebec province: finding that Bill C-17 did not seem to increase the rate at which the firearm suicide rate was already declining. However, other researchers have criticized this 2008 study for looking at too short a time period and not taking account of the fact that the regulations in C-17 were implemented gradually.

A 1990 study compared suicide rates in the Vancouver, British Columbia, Canada metropolitan area (where gun control laws were more restrictive) with those in the nearby city of Seattle, Washington in the US. The overall suicide rate was essentially the same in the two locations, but the suicide rate among 15 to 24 year olds was about 40 percent higher in Seattle than in Vancouver. The authors concluded that "restricting access to handguns might be expected to reduce the suicide rate in persons 15 to 24 years old, but ... it probably would not reduce the overall suicide rate." A study that looked at provincial gun ownership rates and associated suicide rates found no significant correlations with overall suicide rates.

A 2011 study looked at gun control passed in Canada between 1974 and 2004 and found that gun laws were responsible for 5 to 10 percent drops in firearm homicides. The study found that the homicide reduction effects of Canadian gun legislation remained even after accounting for sociodemographic and economic factors associated with homicide rates.

A 2012 study looked at gun control laws passed in Canada from 1974 to 2008 and found no evidence that these laws had a beneficial effect on reducing firearm homicide rates. According to the study, "other factors found to be associated with homicide rates were median age, unemployment, immigration rates, percentage of population in low-income bracket, Gini index of income equality, population per police officer, and incarceration rate."

A 2013 study of the 1995 Canadian gun control law Firearms Act reported little evidence that this law significantly reduced rates of lethal gun violence against women.

A 2020 study examining laws passed from 1981 to 2016 found no significant changes in overall homicide or suicide rates following changes in legislation. In addition, it also found that firearm ownership by province was not correlated to overall suicide rates by province.

Australia

In 1988 and 1996, gun control laws were enacted in the Australian state of Victoria, both times following mass shootings. A 2004 study found that in the context of these laws, overall firearm-related deaths, especially suicides, declined dramatically. A 1995 study found preliminary evidence that gun control legislation enacted in Queensland, Australia, reduced suicide rates there.

A 2006 study by gun lobby-affiliated researchers Jeanine Baker and Samara McPhedran found that, after Australia enacted the gun control law, National Firearms Agreement (NFA), in 1996, gun-related suicides may have been affected, but no other parameter appeared to have been.

Another 2006 study, led by Simon Chapman, found that, after this law was enacted in 1996, Australia spent more than a decade without any mass shootings, and gun-related deaths (especially suicides) declined dramatically. The study, which looked at firearm deaths before and after the implementation of the 1996 gun control reforms and the effects of control on mass shootings, homicides, and suicides, found: "an accelerated decline in firearm deaths, particularly suicides" and that, removing "rapid firing firearms may be an effective way of reducing mass shootings, firearm homicides and firearm suicides." The researchers of Chapman's study also criticized the Baker and McPhedran study for using a time-series analysis despite the fact that, according to Chapman et al., "calculating mortality rates and then treating them as a number in a time series ignores the natural variability inherent in the counts that make up the numerator of the rate." Chapman et al. also said that Baker and McPhedran used the Box–Jenkins model inappropriately.

A study in 2010 also looked at the effects of the NFA on gun-related deaths, finding that the law "did not have any large effects on reducing firearm homicide or suicide rates," although David Hemenway has criticized this study for using a structural break test despite the fact that such tests can miss the effects of policies in the presence of lags, or when the effect occurs over several years. Another study, published the same year, found that Australia's gun buyback program reduced gun-related suicide rates by almost 80%, while non-gun death rates were not significantly affected.

Other research has argued that, although gun suicide rates fell after the NFA was enacted, the NFA may not have been responsible for this decrease and "a change in social and cultural attitudes" may have instead been at least partly responsible.

A 2011 study found that "Australia's prohibition of certain types of firearms" has not prevented mass shootings. In 2016, Chapman co-authored another study, which found that there were no mass shootings in the country after the NFA was passed (as of May 2016), and that gun-related death rates declined more quickly after the NFA than they did before it. However, the study also found that non-gun suicide and homicide rates declined even more quickly after the NFA, leading the authors to conclude that "it is not possible to determine whether the change in firearm deaths can be attributed to the gun law reforms."

Other countries

A 2007 study found evidence that gun control laws passed in Austria in 1997 reduced the rates of firearm suicide and homicide in that country.

In Brazil, after disarmament laws were passed in 2003, gun-related mortality declined by 8% in 2004 relative to the previous year: the first decline observed in a decade. Gun-related hospitalizations also reversed their previous trend by decreasing 4.6% from 2003 to 2004.

A 2006 study found that, after gun control laws were passed in New Zealand in 1992, suicides committed with guns declined significantly, especially among youth. However, this study also found that overall suicide rates did not change significantly. A case–control study conducted in New Zealand found that gun ownership was significantly associated with a greater risk of gun suicides, but not suicides overall.

A 2010 study looked at the effect of a policy adopted by the Israel Defense Forces, which restricted access to guns among adolescents, on suicide rates and found that, "Following the policy change, suicide rates decreased significantly by 40%." The authors concluded that, "The results of this study illustrate the ability of a relatively simple change in policy to have a major impact on suicide rates."

A 2013 study showed that, after the Military of Switzerland adopted the Army XXI reform which restricted gun availability, in 2003, suicide rates – both overall and firearm-related – decreased.

Also in 2013, a study looking at four restrictive gun laws passed in Norway found that two of them may have reduced firearm mortality among men, but that the evidence was less conclusive with respect to all of the laws they studied.

A 2014 study found that, after South Africa's Firearm Control Act was passed in 2000, homicide rates in the country declined and concluded that, "stricter gun control mediated by the FCA accounted for a significant decrease in homicide overall, and firearm homicide in particular, during the study period [2001–2005]."

A study in 2000 found that a ban on carrying guns in Colombia was associated with reductions in homicide rates in two cities in the country, namely, Cali and Bogotá.