Forget about double-bagging, and no bags at all for items that have a handle (milk containers, for example). Supervalu, which owns several other chains around the country, figures it can save a few million dollars by putting more items in the bag or skipping the bag altogether. And plastic bags are by far the preference (they cost two cents each versus paper which runs five). From the WSJ:
Managers from nine of Supervalu's chains join a monthly conference call to review bagging figures. All Northwest cashiers and baggers must also take a 41-question quiz on bagging. For instance, how would you pack a collection of up to 28 items in the fewest bags? Supervalu has made the quiz available across the country and is studying whether to encourage weekly evaluations company-wide.
Saving a few million dollars may not seem like that big a deal for a chain that reported $40.6 billion in annual revenue last year (sounds like a foolish economy to me), but Supervalu has had 11 consecutive quarters of sales declines at stores open at least a year. Obviously there's pressure to save money.