individual has a valid permit issued in another jurisdiction. In addition, the New York State statutory definition of a "loaded firearm" differs significantly from what may be commonly understood, as simply possessing any ammunition along with a weapon capable of firing such ammunition satisfies the legal definition of a loaded firearm in New York. The large variability of state carry laws has resulted in confusing circumstances where a person in Vermont (which requires no license of any kind to carry a concealed weapon by anyone who is not prohibited by law), could unwittingly travel into the adjacent state of New York, where such individual, despite acting entirely within the law of Vermont, would then face a mandatory 3.5 year prison sentence simply for accidentally crossing the state's border into New York. These circumstances are aggravated by the fact that many NYS police departments as well as the New York State Police do not recognize the protections granted federally under the Firearm Owners Protection Act, which was intended to prevent such prosecutions. Effect on crime and deaths Research has had mixed results, indicating variously that right-to-carry laws have no impact on violent crime, that they increase violent crime, and that they decrease violent crime. A 2020 study by the RAND Corporation of over 200 combinations of gun policies and outcomes found "supportive evidence that shall-issue concealed carry laws are associated with increased firearm homicides and total homicides". They also found supportive evidence that child access prevention laws reduce firearm homicides and self-injuries among youth, and further evidence supporting the conclusion that stand-your-ground laws are associated with increased levels of firearm homicides. The researchers credit a much greater investment in gun safety research over the past few years with providing this and other more recent studies with stronger and more reliable evidence. A 2004 review of the existing literature by the National Academy of Sciences found that the results of existing studies were sensitive to the specification and time period examined, and concluded that a causal link between right-to-carry laws and crime rates cannot be shown. Quinnipiac University economist Mark Gius summarized literature published between 1993 and 2005, and found that ten papers suggested that permissive CCW laws reduce crime, one paper suggested they increase crime, and nine papers showed no definitive results. A 2017 review of the existing literature concluded, "Given the most recent evidence, we conclude with considerable confidence that