Family law: Marriage and other equivalent or similar unions and status: Cohabitation

Cohabitation is an arrangement where two people are not married but live together. They are often involved in a romantic or sexually intimate relationship on a long-term or permanent basis. Such arrangements have become increasingly common in Western countries since the late 20th century, being led by changing social views, especially regarding marriage, gender roles and religion.

More broadly, the term cohabitation can mean any number of people living together. To "cohabit", in a broad sense, means to "coexist". The origin of the term comes from the mid-16th century, from the Latin cohabitare, from co- 'together' + habitare 'dwell'.

Reasons for cohabitation in the United States.

Today, cohabitation in the United States is often a part of the dating process. In fact, "cohabitation is increasingly becoming the first coresidential union formed among young adults." In 1996, more than two-thirds of married couples in the US said that they lived together before getting married. "In 1994, there were 3.7 million cohabiting couples in the United States." This is a major increase from a few decades ago. According to Dr. Galena Rhoades, "Before 1970, living together outside marriage was uncommon, but by the late 1990s at least 50% to 60% of couples lived together premaritally.

People may live together for a number of reasons. Cohabitants could live together in order to save money, because of the convenience of living with another, or a need to find housing. Lower income individuals facing financial uncertainty may delay or avoid marriage, not only because of the difficulty of paying for a wedding but also because of fear of financial hardship if a marriage were to end in divorce.

When given a survey of the reasons why they cohabit, most couples listed reasons such as spending more time together, convenience based reasons, and testing their relationships, while few gave the reason that they do not believe in marriage. The extremely high costs of housing and tight budgets of today's economy are also factors that can lead a couple to cohabitation.

Today sixty percent of all marriages are preceded by a period of cohabitation. Researchers suggest that couples live together as a way of trying out marriage to test compatibility with their partners, while still having the option of ending the relationship without legal implications. In 1996, "More than three-quarters of all cohabitors report plans to marry their partners, which implies that most of them viewed cohabitation as a prelude to marriage. Cohabitation shares many qualities with marriage, often couples who are cohabiting share a residence, personal resources, exclude intimate relations with others and, in more than 10% of cohabiting couples, have children. "Many young adults believe cohabitation is a good way to test their relationships prior to marriage. Couples who have plans to marry before moving in together or who are engaged before cohabiting typically marry within two years of living together. The state of cohabitation of a couple often ends either in marriage or in break-up; according to a 1996 study about 10% of cohabiting unions remained in this state for more than five years. According to a survey done by The National Center for Health Statistics, "over half of marriages from 1990-1994 among women began as cohabitation.

Cohabitation can be an alternative to marriage in situations where marriage is not possible for financial or family reasons (such as same-sex, interracial or interreligious marriages).