Dialogue or issue divergence in the political campaign?

We incorporate the media priming effects to explain how politicians can affect voters' preferences on issues during the political campaign. We adapt well-known terms of international trade, such as absolute advantage and comparative advantage, to the context of parties' competition in political issues. We show that when either each party has an absolute advantage on a different issue or when parties have "high" comparative advantage on a different issue, the political campaign will consist of issue-emphasis divergence. However, when a party has an absolute advantage on both issues but the parties' comparative advantage is not "high enough", the political campaign will consist of issue engagement or dialogue. Our results conciliate two separated theories concerning whether there must be dialogue or issue-emphasis divergence in the political campaign.