經濟投票與政黨輪替—以台灣縣市長選舉為例

Abstract

在經濟與政治關係日益密切的今日，經濟表現是否會影響選舉結果已成為學者所關切的議題。目前西方國家，特別是美國，針對中央層級選舉經濟投票行為方面之研究已有高度共識，即經濟表現不佳，會對執政黨的選情不利。至於地方經濟表現對州長選舉有無影響的實證結果，則較為分歧。本文將經濟投票理論應用至台灣縣市長選舉，以台灣21個縣市在1989年至2001年4屆的縣市長選舉作為研究對象，探討致使地方首長選舉結果出現政黨輪替的可能變數，已彌補現有文獻僅考量政治層面、以及中央層級選舉之不足。\n 經由Probit模型估計後發現，地方失業率於選舉年惡化並不會影響縣市長選舉結果；反而是全國失業率對選舉結果有顯著影響。一般而言，總統政黨執政之縣市皆較非總統政黨執政之縣市不易發生政黨輪替，但若全國失業率於選前攀升，則前者所享有的相對優勢會因此而降低，連帶使其被輪替的機率提升。至於另一全國經濟指標物價膨脹率，則不如全國失業率有影響力，即使物價於選舉年上漲，總統政黨執政縣市出現政黨輪替的機率，亦未有隨之提升的態勢。\n 另外，在政治變數部分，現任者競選連任有利於現任執政政黨於選戰中勝出；府會是否同黨對選舉結果則無顯著影響。而本文依據邊際效用遞減法則提出的假設亦得到證實，即一黨連任屆數與其發生政黨輪替的機率呈正向關係。\n 最後，關於時間及縣市虛擬變數部分，本文發現，2001年14屆縣市長選舉發生政黨輪替的機率為4屆之首；而21縣市中，則以嘉義縣、屏東縣、新竹市、台中市、台中縣及基隆市，分居最易發生政黨輪替縣市的前五名。

Substantial scholarly attention has been at the relationship between economic conditions and election outcomes in most western democratic countries, especially in the United States. Most Studies focused mainly on presidential or congressional elections have indicated a solid evidence that the worse economic conditions will be unfavorable to the incumbents to win the elections. Compared with those coincide conclusions, the results about economic voting in state elections are more discrepancy.\n This paper applies the economic voting theory to analyze the county magistrates and city mayors elections in Taiwan and uses a county-and city-level panel data from 1989 to 2001 to examine the possible factors which cause the party rotation of the county magistrates and city mayors elections. After estimating Probit model, the primary finding is that the local unemployment rates have no impact on election outcomes of the county magistrates and city mayors. Instead, the national unemployment rates have a significant effect on election outcomes. Generally, the probabilities of party rotation of the counties and cities ruled by the president’s party are lower than others. However, this advantage will be damaged as the national unemployment rate is higher in the election year than that in the previous year. As to the inflation rates, the other national economical index, are not as influential as the national unemployment rates. For all rising in the election year, the probabilities of party rotation won’t go up.\n Additionally, about the political variables, the incumbents are more likely to defeat the challengers and renew their term of office; it has no significant impact on election outcomes whether the incumbent governors and city or county councils are of the same party. The hypothesis which derives from the law of diminishing marginal utility is also proved. The longer the governing party rules the county or city, the higher the probability of party rotation for this county or city.\n Finally, the probability of party rotation of the 14th county magistrates and city mayors election is the highest from 1989 to 2001. Chiayi County, Pingdong County, Hsinchu City, Taichung City, Taichung County and Keelung City are the top five ones of the twenty-one counties and cities in terms of the frequency of party rotation.