Without scientific rigor, we KNOW nothing about success or failures.
Scientific rigor of what success or failures?
If this was true then WHY whould we need police to begin with, or government for that matter. You assume that CCW will reduce police load, presumably because crime will be less prevalent. Yet you admit that the work done by Lott is flawed.
The work done by Lott is hardly flawed. In fact, the work of John Lott and David Mustard is so sound that it has caused a fundamental shift within the academic community. No longer is the debate among serious scholars over an 'increase' or 'decrease' in crime rates due to CCW. The debate is now over the degree or strength of the protective effect by deterrence (i.e. how much it decreases crime by deterrence).
Lott identified a 'range' of deterrent effect strength within a statistically credible confidence interval, ranging from nearly insignificant to substantial, depending upon how conservatively or liberally one wants to interpret the data. Instead of chosing a 'safe' median number or even the lower boundary, Lott chose the 'rosiest' picture. Conservatively interpreting the data still produces a net deterrent effect, but one that is negligible.
I'm perfectly willing to accept the lower boundary, because it subverts the position of CCW opponents just as well. In proving CCW opponents wrong, one need not show that CCW actually decreases crime in any meaningful way, simply proving that CCW doesn't increase crime goes just as far to those ends.
You can't argue that CCW have no effect (see your P about no meaningful effect) AND argue that CCW have a beneficial effect.
Sure you can, it will be my pleasure to educate you.
At the heart of the Statist mind is an ideological loathing of personal independence and self-reliance that does not admit of owing its very existance to the blessings of The Omnipotent State. You can't very well have a society utterly dependent upon the mercies of government if people get some crazy idea that they can do just as well or even better without the incessant if not unwelcome and onerous 'help' of the 'crusading uplifters' (see H.L. Mencken). You don't know you need 'help', but you do, because I said so - end of discussion.
When New York City enacted the Sullivan Law, one of the motivating factors was the fear by police that shop owners would 'take the law into their own hands' in response to being 'squeezed' by various groups for 'protection money'. You know: 'Unless pay us so much per week, we can't protect you from the bad things that we might do to you or your family.'
It was bad enough that shop owners were being squeezed by organized crime thugs, but to have highly corrupt police officers come behind them and say 'Unless you pay us so much per week...' was driving people nearly to the breaking point. Get the picture?
Some immigrant shop owners came to this country for 'liberty or death' and there were occassional shoot-outs between shop owners driven to the breaking point and organized crime thugs. This sets a baaaaad precedent, others might follow this example. You certainly cannot have people protecting themselves because it makes the police services look ineffective and incompetent.
So the answer is to crack-down on gun ownership instead of organized crime - natch - since the police were highly corrupted by organized crime, thus the Sullivan Law. Even though big city police departments are no longer as corrupted by organized crime, the effect on the public's perception of their police services caused by citizens dialing .357 instead of 911 is just as contemporary: it makes the police look ineffective. "Leave it to the professionals" police officials in big cities such as New York City often advise when publicly commenting on citizens defending themselves.
When people begin to perceive their police services as ineffective, they begin to ask pesky questions that Statists hate, such as 'Why in the hell am I paying all these taxes?' Statists hate that question more than anything. Getting the picture...yet?
The reason CCW has no meaningful effect on crime is because too few people choose to accept responsibility for their own safety and protection. Among CCW states, the percentage of the adult population who are permitted to carry a concealed weapon at any one time ranges around 2% ~ 3%. Too few to have a greater deterrent effect on crime rates, but definitely enough to detect whether or not these people are running around shooting-up their states.
Several states track arrests of their concealed weapons holders when they run afoul of the law, and without exception, concealed weapons permit holders as a group are among the most law-abiding of any identifiable group. When they do run afoul of the law, its more often not related to firearms. When it is related to firearms, its more often a technical violation such as unwittingly carrying a firearm into a prohibited area, failing to have required paperwork on their person when they are carrying, or forgetting to renew their license and carrying while no longer permitted, not a crime of intent or violence.