Australia’s family tax system is “unfair”, according to leading demographer Professor Peter McDonald, as birth rates fall and the migration debate intensifies. Australia’s family tax system is “unfair”, according to leading demographer Professor Peter McDonald, as birth rates fall and the migration debate intensifies. Credit: SuppliedAustralia’s family tax system is “unfair”, according to leading demographer Professor Peter McDonald, as birthrates fall and the migration debate intensifies. “We’ve been taxing away the family tax benefit and I’m a pro-child person so I think that’s unfair,” Professor McDonald told the podcast. The issue is now colliding with a broader political fight over migration, tax and childcare.