The survey is particularly useful to researchers because it asked respondents not just whether they own guns, but how many and what types of guns they own. This makes for one of the clearest pictures yet of American gun ownership, showing the concentration of most guns in the hands of a small fraction of American adults.
The study found that 22 percent of American adults say they personally own a firearm. This is lower than the percentages reported in some other recent surveys, such as those by the Pew Research Center (31 percent) and Gallup (28 percent).
Based on the percentage of people owning guns and the number of guns that respondents reported owning, the survey estimates that 265 million guns are in circulation, or more than one for every adult. This is lower than other estimates, which put the number of guns in circulation at 300 million or more.
Gun rights advocates are often skeptical of gun-ownership surveys, saying that many owners may not disclose the presence of guns to a stranger over the phone or in person. Survey researchers have generally found little evidence to support this claim. The Harvard-Northeastern survey was conducted anonymously via an online panel. The researchers told the Guardian newspaper that they did not receive any pushback from respondents about the questions, leading them to be confident in the results.
The finding that the overwhelming majority of firearms are owned by a small number of adults isn't particularly surprising. Similar patterns of concentration are seen with many other consumer goods and services, from alcohol to health care. The researchers who conducted the study say that most gun owners cite a need for protection from other people as a primary reason to own guns.
"When I look at our survey, what I see is a population that is living in fear," Deb Azrael, a Harvard researcher and one of the study's lead authors, told the nonprofit news organization the Trace. "They are buying handguns to protect themselves against bad guys, they store their guns ready-to-use because of bad guys, and they believe that their guns make them safer."
This shows a significant shift from the 1990s, when most gun owners said they owned firearms primarily for hunting and target shooting.
What Azrael and her colleagues don't know is whether owning many guns is a greater risk factor for violence, suicide or accidental injury than owning, say, one or two guns. They will be publishing their full study results in an academic journal next year.