The 1983 change in surplus vote transfer procedures for the Australian senate and its consequences for the single transferable vote

Among the 1983 changes to the electoral rules for Australian Senate elections using the Single Transferable Vote (STV) was a new procedure for determining the transfer of vote surpluses. The adoption of this modified (‘inclusive’) Gregory method has tended to be overlooked in the literature, yet as this article shows—using both hypothetical and real-world examples—it incorporates an anomaly that could have significance for electoral outcomes. This has important implications not only with regard to whether the ‘correct’ candidate is elected, but also for wider social choice debates over the quasi-chaotic nature of STV.