Children living with married opposite-sex parents were more likely to graduate from high school than peers living with cohabiting, single, or same-sex parents, according to a new study in the Review of the Economics of Households.

This finding is consistent with the decades of research on children’s educational outcomes and family structure. However, this study is relatively unique because it uses data (a 20 percent sample of the 2006 Canadian census) that offers a sufficiently large nationally representative sample of children (ages 17–22) in same-sex-parent homes. So far, only four studies analyzing three U.S. datasets offer such or similar data (two on the 2000 U.S. Census, one on the Early Childhood Longitudinal Study, and another on the New Family Structure Study).

The Canadian data has several advantages for studying the topic, including:

  • In Canada, taxation and government benefits have been available to same-sex couples since 1997, and Canadian law recognized same-sex marriage beginning in 2005.
  • Children self-identified as living with same-sex parents.

Specifically, the study looks at the likelihood of graduating from high school. It identifies six family types: married opposite-sex (which may include remarried parents), common law opposite-sex, gay parents (two dads, married or common law); lesbian parents (two moms, married or common law), single mothers, and single fathers. It also accounts for important characteristics of children and parents.

In sum, the study finds that, compared to peers living with married opposite-sex parents, children living with gay parents had lower odds of graduating from high school—they were 69 percent as likely to graduate—and those living with lesbian parents were 60 percent as likely. However, the difference between children of married opposite-sex parents and those living with lesbian parents was not statistically significant (that is, the study cannot rule out, with sufficient statistical certainty, the possibility that the observed difference in this particular case was due to random chance, not actual differences).

Interestingly, both the children’s and parents’ gender appears to matter. When the study examined boys and girls separately, it found that girls living with lesbian parents were 45 percent as likely to graduate as those living with married opposite-sex parents, and girls living with gay parents were 15 percent as likely.

School attendance levels did not explain why children living with married opposite-sex parents were more likely to graduate. Moreover, by considering the children’s disability status and whether they are the same race as their parents, the study partially accounts for the nature of the child–parent relationship—for example, if the children are adopted.

The emerging evidence based on robust samples is consistent with the existing research: Children’s well-being is linked to their family form and stability and parental characteristics. This evidence does not support claims that “no differences” are discernible in outcomes among children who experience new family structures. Children tend to do best when raised by their married biological mother and father.