GRETA GILBERTSON was caught off guard recently when her 9-year-old daughter, who attends a private school on the Upper West Side, requested a cellphone.

"I sort of snapped at her," recalled Ms. Gilbertson, an assistant professor at Fordham University in the Bronx. "I said, 'Don't think that you're one of the rich kids, because you're not.' " Though her daughter rarely expresses envy of her more affluent friends, Ms. Gilbertson said, it was an "unedited moment" revealing her anxiety over being in a world where other parents have more money than she does.

Carol Paik, a former lawyer who is married to a partner at a prominent New York law firm, found herself on the other side of that money equation. When she returned to school in 2002 to get her M.F.A. in creative writing at Columbia, her diamond engagement ring attracted particular attention from her new group of friends. "When I was working," she said, "I never thought about the ring, it seemed unremarkable."

But at school, she said, "People said things like, 'That's a really big diamond,' and not necessarily in a complimentary way." So she began taking off the ring before class.