Originally Posted by
Giz
(Remember, to make the OP study "work" you'll need to explain a 13-15% rise in crime as being the work of people who commit 1-2% of offences... so you need to show the arrest rates vs actual crime rates as being out of whack by a factor of 10.)
Remember, the OP's claim is not that lawful carriers will commit less crime, but that they will prevent more crime: Good guys with guns will stop bad guys with guns. The prediction is that in addition to not committing crimes themselves, they will prevent others from committing more crimes.
One obvious flaw with the OP's thesis is inherent in the claim itself: A good guy with a gun stops a bad guy with a gun. But this only comes into play if the bad guy starts using his gun. And at that point, the incident gets written up as a violent crime regardless of how it turns out. If a bad guy opens fire, and a good guy shoots him dead before the bad guy hits anyone, that supports the claim that a good guy with a gun stops a bad guy with a gun. But the statistics will still say a violent crime was committed there, even though a good guy with a gun was present.
So I question the premise of the OP, and the usefulness of the cited study. To really understand the effect of good guys with guns on bad guys with guns, we'd have to look at statistics having to do with how many times the two encountered each other, and what the outcomes were.
For the moment, all we can really say is that lawful firearms carriers tend to be statistically less criminal and violent than unlawful carriers. And that by itself is a positive outcome of permitting lawful carry, even if good guys with guns have no other effect on the violent criminal activities of bad guys with guns.