The Productivity Commission has recommended undoing the controversial 2018 changes to the distribution of goods and services tax (GST) revenue between Australian states, which cost taxpayers an estimated A$23 billion. The report criticises the Morrison government's decision to give Western Australia billions in extra GST funds at the expense of other states, calling it a 'costly mistake' that disrupted the system's core objectives. The reforms, intended to address disparities in state revenue capacity and service costs, instead created a more complex and inequitable distribution model. The commission argues that WA received 113% of its assessed fiscal needs under the new system, while other states only got 98%, with additional federal top-up payments funded by all taxpayers. The review highlights how the changes encouraged unproductive interstate lobbying and rivalry, undermining cooperative federalism. The recommended solution is to revert to the pre-2018 system, which balanced state revenue capacity and service costs through annual assessments by the Commonwealth Grants Commission. Critics argue the 2018 reforms were a political expedient that prioritised WA's interests over national fairness.