「藍白合」沒成，選票怎麼分？ －2024年總統大選三腳督之策略性投票分析

Abstract

本研究旨在探討2024年中華民國總統大選「三腳督」競爭局勢下，選民是否因「藍白合破局」而產生策略性投票行為。本文結合杜弗傑法則與理性選民理論作為分析基礎，採用TEDS2024選前與選後定群查資料，透過logit模型檢驗策略性投票傾向與實際投票類型之影響因素。 研究結果顯示，「主觀勝選預期」與「統獨立場」為影響策略性投票的主要因素。當非泛綠選民認為「賴清德最可能當選」時，策略性投票行為的發生機率顯著上升；立場偏統一者也更傾向以策略投票防止不偏好的候選人當選。 在人口特徵方面，青年與中年選民以及女性選民在非泛綠群體中更傾向策略性投票，且女性在「棄柯保侯」群體中比例較高，顯示性別因素與候選人形象之間存在交互影響。政黨認同則呈現負向影響，泛藍與白色認同者相較無政黨認同者較不傾向策略投票，意味著藍白支持者在破局後多傾向維持自身偏好。 相對於策略投票者，本研究亦發現「非柯不投」群體除了「白色認同」在柯文哲支持者穩定性上具關鍵作用；另一方面亦顯示，在競選壓力下「白色認同」與「男性」仍能保持對柯文哲的支持。 本文研究結果證實，2024年總統大選三腳督競爭格局確實激發部分選民策略性投票，然而「藍白合破局」亦反而加劇選民之「誠實投票」行為。特別是「非柯不投」的選民群體，已呈現具有黏著性的白色認同結構。雖然策略性投票比例偏低，但在藍白競爭與第三勢力崛起的情況下，少數轉向票仍可能左右結果，尤其當藍白雙方皆意圖爭奪「第二名」並集中票源時，策略性投票依然具有關鍵性與研究價值。本研究的分析有助於理解三腳督選戰下的投票行為特徵，並為未來多方競爭格局中的選舉策略與政黨競爭提供啟示。

This study investigates whether strategic voting emerged among voters during Taiwan’s 2024 presidential election under the “three-way race” scenario, particularly following the breakdown of the Kuomintang (KMT)–Taiwan People’s Party (TPP) alliance. Drawing on Duverger’s Law and rational choice theory, this research utilizes pre- and post-election panel data from TEDS 2024 and employs logit models to examine both the propensity for strategic voting and the factors influencing actual vote choices. The findings reveal that subjective winning expectations and unification–independence stances are key drivers of strategic voting. When non–pan-Green voters believed Lai Ching-te (DPP) was most likely to win, the likelihood of casting a strategic vote increased significantly. Among demographic factors, younger, middle-aged, and female voters were more inclined to vote strategically, with women playing a notable role in the “abandon Ko Wen-je for Hou Yu-ih” (KMT) pattern. In contrast, the “Only-for-Ko” voters demonstrate a strong white identity alignment, showing loyalty to Ko Wen-je even under electoral pressure. Although the overall proportion of strategic voting was not dominant, it still had potential influence, especially as both KMT and TPP sought to secure the second place to challenge the DPP. The study contributes to understanding voting behavior in multi-party contests and offers implications for future electoral strategies and party competition in Taiwan.