Great stats, research……
Of course, all people, in every place “studied" simply do not support the findings.
Marriage, as an institution, is a legal and religious construct. As such, those institutions benefit from the contract entered into by two people.
I do support a decision to get married but I do not accept that children of people who cohabitate suffer because of that agreement.
One only need observe aboriginals and tribes of people “off of the grid” whose children enjoy the benefit of a life long commitment without the burden of legal or religious edicts.