How Parties Launch Agendas: Evidence From 5.5 Million Tweets

Why This Question Matters

Political agenda-setting is central to how issues gain public salience and move onto institutional decision agendas. Daniel Sandvej Eriksen challenges a common, but under-theorized, assumption: that political parties do more than respond to events—they can proactively initiate and elevate issues. Clarifying how parties exercise this agency matters for understanding media dynamics, parliamentary debate, and party strategy.

The Issue Initiation Model

Eriksen develops the Issue Initiation Model to theorize two linked party strategies: initiation (introducing or foregrounding an issue) and elevation (raising its prominence so other actors pay attention). The model identifies the mechanisms through which parties can deliberately create momentum for topics—from coordinated messaging to timed escalations that aim to attract media and parliamentary attention.

Data and Empirical Approach

The model is tested using a large digital-trace dataset spanning 2015–2022 in two democracies: the United Kingdom and Denmark. The empirical materials include:

• More than 5.5 million tweets from political parties and their Members of Parliament;
• Over 750,000 news articles from national media; and
• 419,000 parliamentary questions.

Analysis links party communications to downstream patterns in media coverage and parliamentary activity to detect evidence of initiation and elevation across contexts.

Key Findings

• Parties and their MPs can proactively redirect attention: coordinated and strategically timed communications are associated with shifts in media and parliamentary attention.
• The results support the model’s distinction between initiating an issue and elevating its prominence, showing that parties do not simply react but can shape the agenda through planned actions.
• Cross-national evidence from the UK and Denmark demonstrates that these mechanisms operate in different parliamentary and media environments, underscoring the model’s broader applicability.

Implications for Agenda-Setting Research

This study brings party agency to the foreground of agenda-setting scholarship and supplies a tested conceptual and empirical toolkit for studying how political actors create issue momentum. The Issue Initiation Model and the accompanying digital-trace evidence invite researchers and practitioners to treat parties as active drivers—rather than passive responders—of public and institutional attention.