[영문]The authors reflect on the use of marital status to study the living arrangements of elderly people (aged 60 years and older) in a comparative perspective. Traditionally, relevant studies have differentiated by marital status and assumed that married people lived together and that unmarried people did not live with partners. However, marital status is a social construct, whereas union status is the residential one, and although marriage is universal, it is different in different places and at different times. Using fairly recent census data from nine countries around the world, the authors examined how well marital status helps indicate union status. They found reason to believe that marital status has been a good indicator of union status in some places at certain times but that it is not always so.