Living Apart Together: 40 Years of Sociodemographic Research on LAT Relationships

This article retraces the history of research on non-cohabiting unions, today commonly called living apart together (LAT) in the international scientific literature, and how they were first brought to light. The notion was first used in 1980 by the Dutch demographer Cees J. Straver, then redefined by Jan Trost and John Haskey in the early 2000s. It was gradually included and operationalized in national and international statistical surveys conducted in the 1990s and 2000s. LAT relationships have been analysed from various angles: comparison of non-cohabiting relationships with other partnerships (marriage and consensual union), comparison of different types of non-cohabiting relationships, and analysis of their outcomes over time. This intellectual history is punctuated by a recurring question: are these relationships the consequence of structural constraints (e.g. long periods in education, difficulty finding a stable job, etc.) or do they reflect the emergence of new values and expectations?