The problem with concealed carry is that it would work great if you could **identify** the bad guy before he gets close enough to attack. However, that's not how robberies occur. Bad guys don't wear signs to identify themselves and they aren't stupid enough to draw their knife or gun 20' away and stand there and wait while you pull out your own gun. No, they will pretend to be innocent and approach close to you and then suddenly they'll pull their own knife or gun, usually behind you if they can, when it's too late for you to do anything about it. There were COPS killed in their patrol car here in Las Vegas and it went down exactly like that. They never saw it coming. There were a number of armed individuals present when Gabrielle Giffords was shot, and what good did it do them? None whatsoever. Not one of them drew a gun. There simply isn't time to react. And if you start pulling your gun on everybody you think might possibly be trying to rob you, pretty soon you're going to shoot some innocent person.
So, if you don't have time to react, what benefit did you get from carrying? If you're carrying, they may shoot you first lest you use your gun on them. At best, you could be robbed not only of your money but of your gun as well. Unless you're going to walk around with your gun in your hand, loaded, cocked and ready, there's not a darned thing you can do about the situation. The best defense is to avoid getting into this situation in the first place. This is why I don't carry a gun on my person or in my car. Please note, I'm not "anti-gun," I am just "pro" common sense. I do keep one under my bed because if anyone enters my house, my alarm and locked bedroom door will give me the time I need to respond and actually use it. But concealed carry in public? That's illogical paranoia. No thanks.