If you just had paper or plastic -- obviously reusable is far more beneficial -- then the paper is worse, and the paper is worse because it weighs four to 10 times more than the plastic, and when we actually compare, from a life cycle perspective, a kilo of plastic and a kilo of paper, the paper is far better, but the functionality of a plastic or a paper bag to carry your groceries home is not done with a kilo of each material.