Gun Control, Concealed Carry, and the White Elephant

So, I've always felt that its admirable to be able to very skeptically review one's own position on a topic and subject it to the same or higher level of scrutiny that you put your opponents' positions.

When I attempt to do this with regards to gun control, I try to be equally critical of authors on both sides that have integrity problems, be it Mr. Bellesiles or Mr. Lott. Having said that, with regards to concealed carry laws, I believe that it is impossible to correlate an increase in crime to liberal CCW laws, and there is, at an absolute minimum, a possibility of correlating a decrease in crime.

Now, as far as I'm concerned, as long as it doesn't significantly increase crime, I'd much rather let people carry guns than not. There is, however, a big white elephant in the corner that no one talks about: illegal carry by law abiding citizens. There are a number of studies that show that people tend to speed when the speed limit is unreasonably low, and likewise, in states with restrictive CCW laws, otherwise law abiding, citizens will illegally carry weapons when in dangerous areas.

So, the problem is that it is hard to figure out to statistically account for the number of people illegally carrying guns that prevent crimes, but never report them. Do liberal CCW laws tend to let people that would otherwise illegally carry act to help other people when they would have held back in fear of prosecution? I've been searching the interweb for a while, and can't come to a strong conclusion.