制度研究上游：制度選擇中游：制度運作下游：制度影響反饋：從下游到上游政治制度憲政體制：總統制、內閣制、半總統制選舉制度：單選區制、比例代表制、SNTV（二者可能有交集）上游+憲政體制研究政治制度中憲政體制的上游研究－為何會採行特定的憲政制度（institutionalchoice）A:政治制度中憲政體制的上游研究－為何會採行特定的憲政制度；B:民主化與民主鞏固的環境；A+B:新興民主國家在民主轉型與轉型後如何決定其憲政體制全面性解釋政黨權力極大化的理性抉擇（大黨喜歡權力集中的制度，小黨喜歡權力分散的制度）制度傳統（正面、反面參考）政治文化外國示範作用（physicalvs.conceptualdistance）體系需求：認同分歧、民主鞏固、經濟改革、外在威脅（民族、民權、民生、對外關係）過程性觀點理性勝出賽局均衡權力／偏好向量分析路徑依循+contingenciesSemi-presidentialismSPmostpopularconstitutionalchoiceby“third-wavedemocracies”From“mixedsystems”and“residualcategory”toDuverger’stripartitedefinition:GovernmentresponsibletoparliamentPresidentdirectlyelectedPresidentwieldingconsiderablepowersDualCLCRsinSPDualchainoflegitimacy,command,andresponsibility(dualCLCRs,coreofSP)ParliamentaryCLCR:governmentresponsibletoparliamentPresidentialCLCR:directlyelectedpresidentplusconsiderablepresidentialpowersArchillesheelSPinNascentDemocraciesPresidentbuttressedbystrongmantraditionanddirectmandatefromvotersParliamentempoweredthroughrepresentingpeopleEnsuingclashoftwoCLCRs,ifpresident-parliamentaryincongruenceLackofexperienceinreconcilingcontradictingtrendsGridlockandchaosPlayedOutinFourModesInteractionmodesbetweenpresidentandparliament:presidentialsupremacy,compromise,cohabitation,andcollisionSuccessfuloutcome:compromiseandcohabitation(mostlyinestablishedSPR);unsuccessfuloutcome(mostlyinnascentSPR)Semi-presidentialism濫觴於歐洲並為眾多新興民主國家採用SpreadofSemi-PresidentialisminTime:1919-1989SpreadofSemi-PresidentialisminTime:1990-