選前民調與邊開票邊投票對策略投票的交互影響：一項實驗研究

Abstract

在民主選舉中，可能因為選民的策略投票行為導致簡單多數決無法完美反映選民的真實偏好，而最常被廣泛討論的兩個導致策略投票的因素為依序投票和選前民調。本研究以實驗室實驗的方式，探討依序投票制度與選前民調是否會影響少數方受試者策略投票的意願與決策時間，並使用混合效果羅吉斯迴歸模型來分析。實驗結果顯示，在依序投票制度下，少數方受試者更傾向於策略投票；同時，公布讓少數方身份曝光的選前民調也會增加少數方受試者策略投票的意願。然而，兩者之間的交互作用並未對受試者策略投票意願產生正向加乘效果，反而有所抵銷。此外，相較於同時投票，依序投票下的受試者花了更長的時間做決策；相較於沒有公布民調，公布民調下的受試者亦如此。總的來說，我們確實發現投票前的資訊揭露會影響部份受試者的投票決策，特別是依序投票可以影響25% 至56% 受試者的投票決定。

In democratic elections, strategic voting behavior among voters may lead to the failure of a plurality voting to perfectly reflect the true preferences of the voters. The two most widely discussed factors leading to strategic voting are sequential voting and pre-election polls. We conduct a laboratory experiment to verify whether the sequential voting system and pre-election polls influence the willingness of minority party subjects to engage in strategic voting and their response time. We analyze these data using mixed-effects logistic regression models. The experimental results show that under the sequential voting system, minority party subjects are more inclined to engage in strategic voting. The results also show that merely informing the identity of the minority party increases the willingness of minority party subjects to engage in strategic voting. However, the interaction between these two factors does not have a positive synergistic effect on subjects’ willingness to engage in strategic voting; instead, it offset each other. Furthermore, subjects under sequential voting spend more time making decisions compared to those under simultaneous voting. Similarly, subjects informed of the minority party’s identity spend more time making decisions compared to those who are not informed. Overall, we found that pre-voting information disclosure influences the voting decisions of some subjects, particularly with sequential voting altering the voting decisions of 25% to 56% of subjects.