一般來說「中間選民」指的是一群自稱不特別偏向某一個政黨或政治立場的選民。然而,選民在調查訪問中口頭所表述的「無意見」、「沒有政黨傾向」不見得是真心話。這個現象可能(已經)使一般選舉調查,就政黨支持者分布的描述出現失真的現象,甚至進一步會造成對於選情的誤判。本研究從概念釐清與「動機推論理論」(partisan-motivated reasoning)視野出發,重新檢討這個現象,並從「隱性選民」(closetpartisan)角度,觀察這些民意調查中這些政黨傾向未表態的民眾的真實意向分布。我們首先設計一組間接測量政黨傾向電訪題,並在 103年 1 月份蒐集了有全國代表性的電訪資料(受訪人數 N =1,072)。我們將這些題目的藍綠分數組成指標(index),以此得分的分布作為辨別藍綠選民的基準,用它來推判隱性選民的政營支持傾向。我們再以電話追訪,將他們在第二次受訪時所表述的真實政黨意向與我們的辨別結果作比較。我們更進一步與四位得分偏向中間點的隱性選民進行深度訪談,深入瞭解他們論述政黨的方式。透過這一系列的分析,本研究一方面提出有效間接測量黨性的電訪題,有助於降低當前政黨題項目無反應比例愈來愈高所帶來的衝擊,另一方面得以為台灣「中間選民」到底是多還是少的這個未解之謎提供線索,以及為動機推論理論的發展提供經驗證據。
Researchers of partisan voters have been assuming that there is a solid difference between "independent" voters and partisan voters (including leaners). This is hardly the case in the Taiwan context, a democracy with a two-party presidential system, where over 40 percent of voters are partisans, but claim to be independent in most telephone surveys. Pollsters, researchers, and journalists have been calculating the distribution of party supporters by either omitting these "independent" voters due to the unavailability of the data, or simply applying counterintuitive formulae to guess the distribution of the respondents with missing data. This study avoid the definition of these not-so-well-defined "independent" voters, but takes aim at these "invisible" or "closet" voters and attempts to the partisan orientation behind their ambivalent answers to telephone surveys. With this in mind, we took a series of steps, including qualitative and quantitative ones. First, we used a representative sample, conducted in January 2014 (N=1,072) in Taiwan via an RDD telephone survey. This survey included the conventional party identification question plus a series of theory-based alternative questions that we evaluated as triggering respondents' mobilized reasoning regarding the two major political parties, the Kuomintang (KMT) and Democratic Progressive Party (DPP). We then created an index for partisan respondents of the two political camps, and applied the score patterns to the closet respondents. In another follow up survey (March 2014) that targeted the closet respondents, we found that the correctness of prediction using the index was about 70%. We then targeted and interviewed the most ambivalent closet voters and explored how their partisan mobilized reasoning was (and failed to be) triggered by the alternative survey questions. We concluded with a few survey questions that future electoral studies can use for probing closet voters. The rich implications of the findings for improving the accuracy of predicting partisan votes, the debates about the characteristics of independent voters, and the development of partisan motivated reasoning theories are discussed