Young adults are considered to be living with their parents or grandparents if their relationship to the household’s reference person is “child” or “grandchild.” A household’s reference person is the person (or one of the people) who own or rent the housing unit in which a household resides; or, if there is no such person, any adult member, excluding roomers, boarders or paid employees. If the house is owned or rented jointly by a married couple, the reference person may be either the husband or the wife.