According to the population census in 2011, 45.2% of the Grand Duchy's residents live together as a couple. Among these people, the majority (88.1%) are married, while 9.1% live together on an informal basis and 2.7% have entered into a civil union (PACS).
The civil union (PACS) is a relatively recent institution in the Grand Duchy; it was introduced by legislation passed on 9 July 2004. It provides legal security in civil, fiscal and social security matters for two people, of the same or different gender, who have decided to live together without getting married.
Since the 2000s, the number of weddings in the Grand Duchy has fallen slightly each year, while the number of divorces has increased slowly but surely.
Given the multicultural nature of society in the Grand Duchy, it is not surprising that in 13.1% of all couples at least one of the partners is not a Luxembourger (mixed couples).
Married people are more likely to have children than people who are living together on an informal basis or have entered into a civil union.