Measuring the Volatility of the Political agenda in Public Opinion and News Media

TL;DR

This paper introduces new quantitative measures to assess the volatility of political agendas using interdisciplinary methods, enabling better understanding of agenda dynamics across media and public opinion.

Contribution

It proposes novel metrics for agenda volatility that integrate political science, communications, and computational techniques, and compares them with existing measures.

Findings

New metrics effectively capture agenda shifts.

Metrics complement traditional measures like Pedersen Index.

Applicable to media and public opinion data in the UK and Germany.

Abstract

Recent election surprises, regime changes, and political shocks indicate that political agendas have become more fast-moving and volatile. The ability to measure the complex dynamics of agenda change and capture the nature and extent of volatility in political systems is therefore more crucial than ever before. This study proposes a definition and operationalization of volatility that combines insights from political science, communications, information theory, and computational techniques. The proposed measures of fractionalization and agenda change encompass the shifting salience of issues in the agenda as a whole and allow the study of agendas across different domains. We evaluate these metrics and compare them to other measures such as issue-level survival rates and the Pedersen Index, which uses public-opinion poll data to measure public agendas, as well as traditional media content to measure media agendas in the UK and Germany. We show how these measures complement existing approaches and could be employed in future agenda-setting research.