競選支出對候選人得票率的影響：以台灣第八屆立委選舉為例

The Effect of Campaign Spending on Votes: Evidence from the 8th Legislative Election in Taiwan

蔡帛軒(Po-Hsuan Tsai)

指導教授 ： 黃景沂

國立臺灣大學/社會科學院/經濟學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01890

摘要

本文利用監察院所提供的競選支出資料，分析2012年台灣第八屆立法委員選舉，檢測參選人競選支出與得票率之間是否有所關連。根據美國學界以Jacobson（1978）為首的傳統競選支出理論，參選人於選舉期間投入的經費確實能提高得票，而且同選區中挑戰者競選支出的邊際效果高於現任者，對此Jacobson認為候選人的支出受限於邊際效用遞減，當現任者的知名度遠高於挑戰者時，現任者的支出相較之下無法再提供選民額外的資訊，因而對於選票的助益較小。另一方面，Moon（2006）的相關研究中將競爭程度納入考量，當候選人的選情越顯膠著，支出的效果亦隨之攀升，此外戰況拉鋸的選區中，現任者支出的邊際效果反而高於挑戰者。由於競選支出和候選人預期得票率具相互連動性（reciprocal relationship），因此除簡單最小平方法（OLS）外，本文亦採取兩階段最小平方法（TSLS）解決內生性問題。最後我們依照候選人所屬政黨的上屆得票率，將各選區分類為選情激烈的拉鋸選區以及局勢相對穩定的非拉鋸選區，發現當候選人落於拉鋸選區時，競選支出有助提升得票率，而且現任者支出的邊際效果高於挑戰者；然而非拉鋸選區中無論候選人現任與否，競選支出皆不符合統計上的顯著性，無法肯定這些經費能對選票有所助益。這兩種型態的選區差異，符合上述Moon的研究發現，而與傳統的Jacobson支出理論相違。

關鍵字

政治獻金法 ； 立法委員選舉 ； 競選支出 ； 邊際效用遞減

並列摘要

Basing on the campaign spending reported to the Control Yuan for the 2012 legislative election, we try to find out whether campaign expenditure affect election results. According to Jacobson (1978)’s research, he confirmed that campaign expenditure can raise votes for the candidates; moreover, in the same district, the marginal return of the incumbent spending is less than that of the challenger. In Jacobson’s view, he thought that both the spending from the challenger and the incumbent were subject to decreasing marginal return. Since the incumbent was well-known to voters, any additional communication would add relatively little to their knowledge. On the other hand, Moon (2006) found that incumbent spending efficiency depends on the marginality of seats; that is, safe incumbent spending is less effective than marginal incumbent. Moreover, marginal incumbent spending is more effective than marginal challenger in Moon’s research. Due to the potential reciprocal relationship between campaign spending and votes, TSLS is also used to solve the endogeneity problem in our work. Lastly, we divide all districts to safe districts and marginal ones according to the previous election, and find that when candidates are in marginal districts, campaign spending can help to raise votes; besides, the marginal return on the incumbent spending is more than that of challengers. However, regardless of the incumbency, spending from candidates in safe districts cannot affect votes. Our findings confirm Moon’s research, but contradict to the traditional view from Jacobson.

並列關鍵字

Campaign Spending ； Legislative Election ； Decreasing Marginal Return

參考文獻

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