Towards integration of the spatial model of party competition and issue ownership theory: a dynamic model of the role of issues in the media, public opinion, and election outcomes

Spatial theories of party competition assume that political parties strive to position themselves in a region of the political space with many voters but not many competitors (Laver & Sergenti, 2011), although they may end up all in a battle for the median voter. Issue ownership theory assumes that parties compete by emphasizing issues that resonate with social cleavages (Budge & Farlie, 1983). Both models can be written as variants from a generalized model that takes both issue positions and issue salience into account. This generalized model assumes a common space of parties, voters and issues that can be derived from distances between voters and parties on salient issues only, thereby relaxing the assumptions of the spatial model as stated by Stokes (1963): “For the spatial model to be applied, the parties and voters of a political system must be able to place themselves on one or more common dimensions”. Content analysis data about the media coverage of campaigns and survey data from Dutch election campaigns in the period 1998-2012 are employed to show first that, after controlling for perceptions held in the last election campaign, voter perceptions of issue saliency and issue positions of parties in the current election campaign can be explained from the news in the news media used by individual voters, and next that the share of seats in Parliament of a political party, when controlling for the share of seats in the previous elections, can be explained by issue perceptions of voters. The results show that many electoral outcomes can already be explained by issue saliency, but that issue positions are the key to predict electoral changes when parties change positions.