Using Quantitative Methods to Compare Elite Political Framing to Mainstream Media Reporting of the Same-Sex Marriage Debate in Australia

Factors that shape public policy debates and political decision-making are important concerns for democratic societies. To understand two elements of this process, we compare elite political discourse to mainstream media coverage in shaping public policy debate and political responsiveness using the case of the same-sex marriage debate in Australia. Of particular interest is the role of elite political actors in framing the public discourse of the debate and how it differs from the mainstream media's reportage of the issue. Using topic modelling and natural language processing methods, we aim to identify the key elite political actors engaging in this policy debate and their framings of the policy problem (and solution) over time and compare that to media coverage of the debate over the same time period. Our unit of analysis is the text of more than 400 Australian political speeches made in the lower house of the federal parliament from 1998 to 2017 and 60,000 news stories in daily newspapers. While the same-sex marriage debate in Australia ultimately led to a voluntary national plebiscite and the majority result was legislated in December 2017, our aim is to understand how (and when) elite political framing of the discourse shifted and shaped political decision-making and how it compares to public engagement with the issue via the mainstream media. The paper uses recent developments in large-scale automated textual analysis and topic modelling techniques to advance understandings of the relationship between public opinion and political elites in policy responsiveness.