Interest aggregators or office chasers? Examining evidence for the representational role of political parties in Australia from the 1960s to the 2000s

This thesis examines whether Australia’s major political parties continue to fulfill their representational role aggregating the interests of different groups in society, and the types of issues on which they can be expected to provide meaningful policy alternatives. These are fundamental questions for political scientists. The willingness and ability of the parties that generally form government in Australia — the centre-left Labor Party and centre-right Liberal-National Coalition — to represent different groups and provide meaningful policy alternatives, is important for democratic politics.
   
   Here I outline a theoretical framework that characterises the major parties as interest aggregators representing diverse electoral alliances made up of politicians, activists, financial contributors and voters, who hold specific issue preferences and are united by key economic policy goals. These actors create a centrifugal force, pushing party policies away from each other in salient areas. Using this framework I contend that the parties matter for policy outcomes, building on the assumption that cleavages in the social structure are reflected in the political system, with policy implementation the result of the competing demands and interests of the parties’ constituencies.
   
   This theoretical model is tested using data largely unique to Australia, including a survey of election candidates conducted at consecutive elections over 24 years and economic policy outcomes measured quarterly over the half century from the early 1960s to the 2000s. These are examined using novel statistical approaches, such as multilevel regression to take into account variation in the data used in these studies, and item response theory models to estimate the latent issue preferences of political actors in Australia.
   
   These are, respectively, some of the first uses of these kinds of multilevel models in Australian political science, and the first time item response theory models have been used to provide a multi-decade analysis of the issue preferences of voters and candidates in this country.
   
   Using these data and methods, I find strong support for the characterisation of the Coalition and Labor Party as interest aggregators, and important constants in the behaviour of the major political parties based around the interests they were established to represent. Voters support parties consistent with a broad view of their economic interests and their issue preferences. The parties also select candidates to represent them at federal elections with similar policy positions to their voters. The interests and preferences of these political actors are reflected in the legislation supported by the parliamentarians they elect, and some of the economic policy outcomes associated with periods of Coalition and Labor incumbency.
   
   By providing a greater understanding of these ongoing differences, and the reasons they continue to exist, this study allows students, scholars and commentators of Australian politics to better interpret the goals and behaviours of political parties and the actors that comprise them.