The Mugger’s Wallet
I don’t know that the “fake wallet” strategy is really all the new or innovative, but I do find the comments interesting. It seems that most of the people are operating on some internally generated fantasy of what a mugging might look like. These fall into a few broad groups:

The Hippies:“…so you’d rather kill some poor bastard down on his luck than part with a few bucks? That’s some good humanity right there. “
So their mugger isn’t a person who has decided to make a career out of taking other peoples property by violence, but a person driven to desperate measures by circumstances.

The Gunfighters:“My mugger’s wallet is a Springfield XD .40 Sub-compact and many hours of training for just such a situation. Make my day.” Life imitates Hollywood, where the hard-bitten gunfighter rids the world of evil-doers to the accolades of the crowd and a hearty pat on the back from local law-enforcement.

The Tough guys:Yeah, I have a body build that makes me look like the kind of guy who beats up muggers for fun. I might put one of these together just so the mugger will feel totally bad ass before I go all ninja on him.
Because the muggers are never bigger, better armed, or working in groups. I once saw a security detail from the US that looked like it was made of football linemen turned bouncers. While that would probably be impressive in a US night club, it didn’t dazzle me to much in country where street kids have AK47’s and two magazines.

The Good Area Guys:I use the “don’t be in places where you’re likely to be mugged” defense.
Because muggers obey some sort of criminal zoning restrictions. At best this is optimizing a statistical trend, but doesn’t really apply to individuals that actually leave their homes occasionally.

There were also some good, thoughtful comments:
The issue isn’t “is their life worth the money in my wallet”, but rather “is their life worth my life”. The act of shooting someone, even in justifiable self defense will undoubtedly cost you more time and money than a stolen wallet.