Simone and Ana are debating the pricing strategy of several airlines. Simone argues, "When airlines restrict discounted tickets to people who book well in advance and stay over on a Saturday, it is not price discrimination, because the restrictions have nothing to do with individual buyers' willingness to pay." However, Ana says, "The airlines' stay-over restrictions are a form of price discrimination, because they roughly split the market into two separate groups that are willing to pay two different amounts." Economists generally agree with Simone and Ana?