Abstract:

Based on political systems theory， an analytical framework comprising six elements such as focusing capacity， public demand， public support， gatekeepers， general environment， and agenda trigger was constructed. Using qualitative comparative analysis （QCA）， the study examined the trigger mechanisms of policy agenda setting based on focal events from six conditional dimensions： public opinion intensity， cumulative effects， issue claims， issue support， information gatekeeping， and contextual framing. The findings reveal that no single political system element constitutes a sufficient condition for policy agenda setting. The trigger of policy agenda setting depends on the interaction of multiple factors， thereby shaping three distinct trigger mechanisms： “public-driven”，“comprehensive-interaction” and “environment-influenced”. Issue support plays a pivotal role in all three triggering mechanisms and is identified as a key driving element for the successful initiation of policy agenda setting.

Key words: policy agenda setting, focal event, trigger mechanism, qualitative comparison analysis