New research suggests a stand-alone plebiscite on same-sex marriage would cost Australia more than half a billion dollars. The modelling by accounting firm PwC Australia found a compulsory vote on marriage equality would cost the Australian economy A$525 million ($589 million).

It estimates that a plebiscite not held on the same day as a federal election would cost the taxpayer A$158 million to organise, A$66 million for the community to fund the for and against campaigns and A$281 million in lost productivity as people take time out to vote. In addition, PwC Australia estimates at least A$20 million in costs associated with the impact on the mental health and wellbeing of Australians.

PwC Australia CEO Luke Sayers called instead for a parliamentary vote as the best mechanism for change. The modelling found that a parliamentary vote involving campaigning but no plebiscite would cost only A$17 million.