Bags of sense?

The question of supermarket plastic bags is in the news again. The official approach seems to be to curb their use, and to this end it is suggested that we should have to pay for every bag we use. But why? As I understand it, these bags can be recycled, so the only problem is collecting them for recycling, given that local authorities don't seem to want to know. And we have a proven blueprint for that - anybody remember "penny on the bottle"? This goes back to the days when all drinks came in glass bottles, and the industry was keen to get as many empty bottles back as possible for reuse, so you got a penny (probably the equivalent of 10p or more in today's money) for every bottle you took back. As kids, we were always on the lookout for discarded bottles so we could get the returns, as it was called. So why not take the same approach with plastic bags? I always think the carrot works better than the stick.