Cohabitation itself doesn't cause ineffective parenting.

Children that are raised in a home with a married mother and father consistently do better in every measure of well-being than their peers who come from divorced or step-parent, single-parent, cohabiting homes.

Not cohabitation but consensus constitutes marriage.

Let women issue a declaration of independence sexually, and absolutely refuse to cohabit with men until they are acknowledged as equals in everything, and the victory would be won in a single week.

Not cohabitation but consensus constitutes marriage.

Children that are raised in a home with a married mother and father consistently do better in every measure of well-being than their peers who come from divorced or step-parent single-parent cohabiting homes.