A few of points.
• The study you've cited by Don Kates and Gary Mauser has nothing to do with Harvard. It is a non-peer reviewed paper which was published in the Harvard Journal of Law and Public Policy, which is a conservative Law Review edited by right-wing Harvard Law students. The study has never been endorsed, reviewed, supported or attributed to any Harvard School faculty.
• Here's a starting point for researching true peer-reviewed research papers from the Harvard School Of Public Health. Overwhelming, these studies find that more guns usually correlate with more deaths.
http://www.hsph.harvard.edu/research...arms-research/
• Mr Kates and Mauser's study has been the subject of substantial criticism, and analysis has shown that much of their data is simply wrong. I'll give you one example to start: their data shows Luxembourg's murder rate as 9.01 per 100,000 citizens. This rather crucial figure propagates discussion throughout the study, but the crucial problem is the placement of a decimal point: the actual rate is 0.91 per 100,000.
• Kates and Mauser conveniently omit the European nations that don't support their findings when they list statistics.
• Kates and Mauser repeatedly refer to the completely debunked studies by Gleck and Lott as supporting material.
There's no doubt that there are aberrations in the comparative statistics of all nations re: gun prevalence vs gun deaths. Cultural factors are, of course, very important: government stability, government and law enforcement corruption, cultural proclivity toward suicide etc. But in general there is substantial evidence proving that less guns means less crime.
Please post a respected peer-reviewed study that proves otherwise if you can. I've yet to see one.