Levitt on Credit Cards

Following up on my post about EFTPOS policies Steven Levitt is commenting on credit cards. Nothing much new there, but one of the commenters makes the very good point that taking cash payments also has costs to the retailer - having cash, making change, risking robbery, and spending time taking the cash to the bank and depositing it. But I guess, unless they banned cash payments altogether there is little marginal cost in taking a cash payment - as they have to do all those things already apart from give change.