A 2009 University of Pennsylvania study financed by the National Institutes of Health looked at the chances of being shot when holding a gun versus not holding a gun. In Pennsylvania, from 2003 to 2006, police sent the epidemiological researchers reports of gun-related assaults soon after they happened. A research firm then matched those victims with similar people in the area who did not own guns through phone surveys conducted by random-digit dialing. (This is the same sort of research setup that goes into studying the link between drunk driving and car crashes or smoking and lung cancer.) With both a gun-owning victim and a non-gun-owning Philadelphian, researchers had a variable and a control group. Then by comparing those who were shot and had a gun on them with the control group, the researchers looked for a correlation--and found one. In the study, someone in possession of a gun was about 4.5 times more likely to be shot. If the victim had a chance to resist, he or she was 5.5 times more likely to be shot.