ok, well clearly here, there is a gender issue, if the mugger is a bloke, and the muggee is a woman, then it's likely that the first advice should be taken, ie drop or throw the bag and run (even though it enforces the idea in the mugger that it's easy to do, and get away with), we wouldn't want our women to get hurt now would we...
i'm a bloke, and i don't think i'd get mugged, and if i were to, then hopefully i'd try and not give in so easily. But i don't carry a handbag, so the chances of someone mugging me are less, it's not so easy to get a blokes wallet.
yes, Birdie, if the mugger pulls a knife, then the mugging dynamic changes, and not being injured by the knife would become a priority.
i'm not suggesting that one should keep hold of possesions when you could get killed, that's just silly, i'm only talking about being mugged (which hopefully isn't likely to get you killed, just slightly injured).
obviously if someone looks like they're going to stab you with a 9" knife several times in vulnerable areas, then you don't hang around, but otherwise, i wouldn't give in too easily.
i should add that i've never been mugged, so i don't know how i would react in the situation, and hopefully never will, but if i get mugged in the future, and i remember, i'll report back on what i did, and if it had any effect.