One-in-three families in Ireland departs from the traditional model of a married couple both of whom are in their first marriage. This is one of many findings to emerge from the most detailed statistical study to-date of the structure of Irish families, which has recently been published.

Other key findings of the report include:

• Alternative family structures are dominated by never-married cohabiting couples and lone mothers (both never-married and divorced or separated). Together with first-time marriages, these four family types account for 92% of families.
• Second relationships and step-families, though they exist in diverse forms, remain relatively rare in Ireland.
• Childless couples with a mean age of less than 45 years are more likely to cohabit than be married, while the vast majority who have children are married.
• In one quarter of cohabiting couples at least one partner was previously married. The mean age of such couples is over 40 years, suggesting that it is not only the recent cohort of younger adults that is taking advantage of the acceptability of cohabitation.
• The likelihood of cohabitation is linked to socio-economic status. Controlling for other background characteristics, including the presence of children, a couple in their thirties who both have third-level qualifications are less than half as likely to cohabit as a couple who both have lower second-level qualifications.
• Cohabitation is more likely among couples that have different religious affiliation and much more likely among couples who have no religion.
• The likelihood that a couple gets married increases sharply after the birth of a first child, regardless of whether the couple is fairly young, i.e. in their twenties, or older.
• Of the 1.15 million children, 75% live with two married parents, 18% with a lone parent and 6% with cohabiting parents.