Large kraft bags cost about 10 cents each. Shopping bags that have handles go for @ 15 cents. Giving you or your favorite charity a nickle is a bargain for the retailer. I have canvass bags that I take with me when I shop, and they have lasted for many years. I sew them when the seam rips, use them for myriad other chores, etc. I figure I've saved my grocer a few hundred dollars over the years.
My points are several. In Europe, where caring about the environment is an ethic both in business and personal life, a system of charging for bags wouldn't seem penurious, as it does to us. Then, the system that has developed here of giving a nickle back is an incentive to the grocer because it saves them money and makes them look good at the same time. Also, if the consumer deeply cares about the environment, they won't care if the store charges for the bag or not, because they'll realize it's their personal responsibility to bring their own cloth bag. Lastly, businesses and public need to be educated to care as much or more about the environmant as they do about a gosh darn nickle.