Are agendas punctuated because of cascades? An empirical assesment of mass media's issue attention in Belgium.

Research has showed that policy agendas' issue attention is invariably punctuated: long periods of incrementalism alternate with short bursts of frenetic activities. In their seminal Politics of Attention, Baumgartner and Jones state that especially friction accounts for this pattern. This paper explores a second mechanims leading to punctuations: imitation and cascading. Political actors sometimes devote a disproportionally large amount of attention to an issue because other actors are doing the same. The paper contributes theoretically by specifying the conditions conducive for political cascades. It contributes empirically by showing that cascades are indeed at least partially responsible for the punctuated pattern of policy agenda's issue attention. Drawing on an extensive and longitudinal data set of Belgian news media, it is substantiated that a considerable part of the punctuatedness of Belgian media attention is due to media imitating each other. It is argued that these cascading processes remain not confined to the mass media butare to be found all over the political system. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]