(with Laron K. Williams)
How do parties decide about how much attention they dedicate to a consensual issue during a campaign, given high degrees of uncertainty? Assuming that parties strategically attempt to attract voters by writing manifestos, we argue that parties use the electoral performance of other parties as a heuristic to mitigate uncertainty and to learn about the relative utility of emphasizing a consensual issue. The empirical analysis employs tools from spatial econometrics and analyzes party manifestos with regards to their emphasis on the environment a valence issue with a niche party being the unequivocal issue owner in 25 EU countries from 1975 to 2015. The results reveal direct transnational dependencies and indirect spillover effects among the parties’ strategies. It further identifies conscious learning rather than mere imitation or independent decision-making as the transnational diffusion mechanism. At the same time, and in line with saliency-based theories, electoral competition mutes the diffusion of electoral strategies at the domestic level.