政黨政治向來為研究憲政運作、民主深化的核心議題。過往的研究，多將政黨政治視為影響憲政與民主的自變項，但憲政特性以及民主轉型的過程，也可能系統性的影響政黨體系，對於政黨體系變遷的規模、機率，存在一定的關連性。基於此，本文以政黨體系變遷為依變數，從制度特性以及民主化背景來觀察政黨體系變遷的特性。核心假設有三：首先，就制度特性而言，直選總統的國家，比起議會內閣制的國家，政黨體系變遷的機率較高、規模較大；第二，以選舉時程而言，也是制度面向的因素，在直選總統的國家中，同時選舉或蜜月選舉，因為總統衣..

Party politics is an important issue to explain the constitutional work and consolidation of a democracy, and especially for newly democracies. If the party system would be affected by different types of constitutional systems and historical legacy, the party system should also be changed. We have three hypotheses: first, we suppose those countries with a directly elected president will have a higher probability for party system change. And the smaller parties are more likely out of parliament. Second, based on the coattail effect, countrie..