Discussion

Broad scientific agreement exists among the responding firearm researchers concerning many aspects of gun violence. In general, agreement exists that in the USA, the proliferation of guns and weak gun laws have created a serious public health problem; guns do not provide the benefits claimed by gun advocates, and stronger gun laws may improve public health and safety.

There is no unanimity about any of the issues, as there is not about even some of the most well-established findings in science (eg, does HIV cause AIDS). But, when there is broad scientific agreement, no one—journalists, bloggers, policy-makers or the public—should engage in ‘he said–she said’ reporting that emphasises the common fact that researchers can be found on both sides of almost any issue.

Our results indicate that where researchers are more likely to believe the scientific evidence is strong, there is also likely to be higher levels of scientific agreement. For example, the evidence that a gun in the home increases the risk for suicide in the USA is very strong and robust. Many case–control studies and ecological studies find that guns substantially increase the suicide risk, and meta-analyses and reviews of the literature reach the conclusion that access to firearms increases the risk of suicide.5 ,6 ,9 ,10 Reviewing this and other evidence, the 2012 National Strategy for Suicide Prevention authored by the US Surgeon General and the National Action Alliance for Suicide Prevention concludes that ‘firearm access is a risk factor for suicide in the United States’.11

Our surveys indicate that for most firearm issues, many researchers do not think the scientific evidence is very strong. This is not surprising given the difficulty firearm researchers have had in obtaining funding.12 This lack of funding for firearms research resulted in a relatively small number of journal articles for such a large public health problem.13

Our results have limitations. First, over 55% of our emails were never opened; so, our overall response rate is only about one-third. We do not know anything about the opinions of the non-responders. We have explored other ways to increase participation, such as trying different subject email lines, with limited success. We had hoped that the very short monthly surveys, rather than one long survey, would lead to high rates of participation. Second, it is possible that authors who were not even asked to respond to the survey might have different opinions from those who were asked. For example, writing a book chapter on firearms or writing in a law journal did not lead to inclusion in the survey, nor did writing an article before 2011, nor being anything other than the first-author of a journal article. Our goal in limiting the group of authors was to make it more likely that the authors were social scientists or epidemiologists who were knowledgeable in the firearms field, while at the same time making our selection process transparent and reproducible. We excluded non-first authors because we felt they were less likely to be knowledgeable about the literature, and because there are usually multiple authors on each public health/medicine article (some of whom are statistical rather than content experts). We did not want to weigh our sample unfairly toward the public health/medical community. We excluded authors who had not written articles since 2011, because they were less likely to be knowledgeable about the recent literature. We focused on social science and epidemiological firearm issues, and excluded medical treatment, forensic and law articles. Third, as in all opinion surveys, the phrasing of the questions can affect the response. Therefore, we tried to phrase the statements in ways as close as possible to the way the claims were being made in the literature or in public discussion. We wrote our survey statements to allow for comparisons to public surveys and to claims in the scientific literature.

We tried to all for comparisons to public surveys and to claims made by politicians, researchers and others. In one survey, we asked: ‘Periodically the Gallup poll asks this exact question of the general public. Please give your own opinion. “Do you think having a gun in the house makes it a safer or a more dangerous place to be?”’ In 2014, Gallup reported that 63% of Americans believed that a gun in the house makes the house safer, up from 47% in 2006.14 By contrast, only 5% of our researcher respondents said guns make the home safer, and 64% said they make the home less safe.

Some gun researchers have been claiming for years that guns are used in self-defence four times more often than they are used in crime.15 ,16 Only 8% of our researcher respondents agreed with that claim, and 73% disagreed. There has also been the claim17 that the change in state-level concealed gun carrying laws from ‘may-issue’ (police discretion) to ‘must issue’ (no police discretion) has reduced crime, a claim that has been highly contested.18 Only 9% of the researchers answering our poll agreed with the claim, while 62% disagreed.

One of the virtues of our ongoing surveys is that we can examine researcher consensus concerning topical issues. For example, in January 2016, an open carry bill in Florida included as a ‘Declaration of Policy’ that ‘The Legislature finds as a matter of public policy and fact that the possession and carrying of weapons and firearms by law-abiding individuals for lawful purposes, including self-defense, enhances public safety’.19 In February 2016, we asked respondents to rate their level of agreement with the following statement: ‘The carrying of firearms by regular citizens enhances public safety’. Only 5% agreed, and 90% disagreed.

Although scientific consensus is not always right, it can be a useful guide to understanding the world. Our approach of surveying researchers is one way to provide information on the level of agreement among researchers concerning what the science says.