多數統治與選舉制度

Majority Rule and Electoral Systems

本文從多數決作為民主政治原則之一的角度出發，討論多數決的優缺點以及其成為民主政治原則的原因。若從多數決的運作原理來看，雖然其可被視為一種匯集個體偏好的機制，但卻存在循環多數的問題。然而，在某些條件的限制下，多數決是一種能夠產生理性集體選擇的方式。接著，本文從選舉場域與決策場域來討論選舉制度的差異以及其形成多數的意義。簡言之，多數的形成會因為不同的目的而有所差異，無法一體視之。最後，本文將前述關於多數決與選舉制度的討論，應用於臺灣政治體制，提出在不同制度的運作下，已經或可能產生的結果。

This article first discusses the pros and cons of majority rule and illustrates the reasons why majority rule is one of the principles of democratic systems. As a mechanism that aggregates individual preferences into a group decision, it is highly likely to produce cyclical majorities. However, with certain restrictions on preferences or choices, a group of rational individuals can collectively produce rational results. Second, this article explains the differences between electoral systems from the perspectives of accountability and representation. A majority is anticipated either in an election or a process of coalition building. Finally, this article takes the Presidential and Legislative elections in Taiwan as examples to illustrate the effects of electoral systems on achieving a majority of votes and seats.