Margot Kahn and Kelly McMasters know that wanting is a very particular feeling. What women desire is constantly changing, of course: time, money, sex, new shoes. But as the editors of a new collection of essays, aptly titled Wanting, tell NPR's Ailsa Chang, they were more interested in exploring the process of yearning for something – and the rules we construct around that longing – than the objects that we ultimately do or do not get.