As a gun control advocate I also find the study a bit too optimistic in crime reduction, and note that I am not alone, since gun control advocates from Johns Hopkins and Harvard School of Public Health, also disagree with the study's findings.
The rub is the 90% reduction, which is unrealistic, perhaps just 'a priori' reasoning. Most gun control groups contend that the best we can hope for in implementing gun regulations is a marginal improvement over existing gun deaths & gun crime. Like 10% to 20% reductions.
The dramatic national decline across the board in violent crime from early 90's to present 2016, was from a record high in violent crime rates, and coincided with a 30 - 35% decline in gun ownership rates during the same time period (along with the clinton anti crime initiative implemented circa 1994), so that dramatic decline cannot scientifically be attributed to either gun control efforts, or 'more guns ie national gunstock'. Less people per capita owning guns I'd go along with.
Experts noted that the laws, which were on the books in only three states, were not actually being implemented in practice.
That “would be the biggest red flag, obviously, when they’re finding huge effects of a law that doesn’t exist”, Daniel Webster, the director of the Johns Hopkins Center for Gun Policy and Research, said. He called the paper’s approach “just not good science”.
While some of the paper’s findings are interesting, it’s “highly questionable” whether other results “are an accurate reflection of reality”, David Hemenway, a leading gun violence researcher at Harvard’s school of public health, wrote in a comment published along with the paper.
Bindu Kalesan, the paper’s lead author, defended its findings as important contributions to an extremely complex and difficult area of research. The criticisms of the paper were “expected”, she wrote.
= new reply since forum marked as read