I heard on the radio that a bag for life (it wasn't specified exactly what kind) has to be reused 47 times before you get a net benefit.
In retrospect, I think it would have been better to mandate that disposable bags be biodegradable e.g. make them out of paper. Or, rather than the "bag tax" going to charity, mandate that it go into recycling research.
I have chunky bags for life, which have been use a few hundred times already.
