This paper models the outcomes of South Australian state lower house elections from 1997 to 2010 under five different ordinal vote counting methods.
The results of the model confirm the findings of Rae (1971) that AV behaves in much the same manner as plurality voting. However, our data show that AV is unique among ordinal voting methods in this regard. In all other ordinal systems modelled, a greater number of parties gain representation in the lower house and in most years no party would win a majority of seats. Additionally, non-AV ordinal methods display a greater sensitivity to subtle changes in voters‘ preference orders.
The paper then considers the wider ramifications of the AV system on political culture in Australia, which at present is characterised by a highly partisan and adversarial tenor. We conclude that the use of a non-AV ordinal voting method would either produce multiparty lower houses (if voters‘ preference orders are assumed to be sincere) or provide an incentive for major party voters not to preference each other last (if voters‘ preferences are assumed to be strategic). In either case, a non-AV ordinal voting system would provide a basis from which a more constructive and less antagonistic political culture could develop.