It's a comment we often hear in response to stories of child neglect: that parenting should require a licence.
Researcher Dr Frank Ainsworth from James Cook University in Australia says that while the suggestion is based on concern for children, it is fraught with problems.
Dr Ainsworth, an adjunct senior principal research fellow with JCU's social work department, reviewed international studies on parental licensing and Australian statistics on children in care.
"Parental licensing is the idea that parenting competence should be demonstrated prior to adults achieving full parental rights. It's a long-standing idea among a host of academic philosophers, political scientists and others interested in children's rights," he said.
His review showed that while the intent was good, the problems that would come with a parental licensing system made it unworkable and open to abuse.
"The biggest problem is the question of parental licensing being a concealed policy of eugenics," he said.
Dr Ainsworth said parental licensing included the notion that while pregnant women would be allowed to give birth, if they were not licensed to raise children the baby would be removed and put up for adoption.
He said the denial of parenting rights would almost certainly fall more heavily on people with higher rates of socio-economic disadvantage.
"You have to remember that denying a parental licence is not the same as denying any other kind of licence, such as a driving licence. There are no alternatives to parenting a child. Parenting denied is final," he said.
Dr Ainsworth said there is also the question of how a testing system would deal with potential parents with an intellectual disability, those with a physical disability, those who are illiterate and migrants who cannot speak English.
"Disadvantaged sections of the community, and their supporters, would be loud in their opposition to any form of parental licensing," he said.
Dr Ainsworth said his study of adoption statistics indicated that even if such a scheme received political support, there may not be enough people wanting to adopt.
"On the evidence and discussion I've reviewed, it's hard to see parental licensing serving anyone well, especially the children it would be intended to help," he said.