Replication Data for Commodity Shocks and Incumbency Effects

Why do incumbents enjoy an electoral advantage in some political settings but suffer from a disadvantage in others? We propose a novel explanation linking variation in incumbency effects with exogenous commodity shocks. While voters attempt to sanction incumbents for economic performance, changes in commodity prices affect their evaluations and condition the electoral fortunes of incumbents vis-à-vis challengers. We test our argument in Brazilian municipalities, combining a plausibly exogenous measure of variation in commodity prices with a close election regression discontinuity design. Our results show that increases in the price of agricultural commodities greatly enhance the prospects of incumbents, while negative shocks exacerbate their incumbency disadvantage, especially in rural municipalities. Further investigation suggests that commodity shocks do not operate via voter learning about candidate quality, changes in the pool of candidates, shifts in voter preferences, or strategic elite investments. Instead, we find suggestive evidence that commodity shocks affect voters’ evaluations through their effect on local economic growth.为何部分政治场景中，在任公职人员(incumbents)能够享有选举优势，而在其他环境下却陷入选举劣势？本文提出一种全新解释，将在任效应(incumbency effects)的差异与外生大宗商品冲击(exogenous commodity shocks)联系起来。尽管选民会试图依据经济表现问责在任公职人员，但大宗商品价格的变动会影响选民的评价，进而左右在任者相较于挑战者的选举命运。本文以巴西各市政辖区为研究样本，将拟外生的大宗商品价格变动指标与紧选断点回归设计(close election regression discontinuity design)相结合，对本文的核心论点进行实证检验。研究结果显示，农产品大宗商品价格上涨会大幅提升在任公职人员的当选前景，而负面冲击则会加剧其选举劣势，这一效应在农村市政辖区中尤为突出。进一步分析表明，大宗商品冲击并未通过以下路径发挥作用：选民对候选人资质的认知变化、候选人队伍的调整、选民偏好的转移，或是精英阶层的战略投资。相反，本文发现佐证性证据显示，大宗商品冲击通过影响地方经济增长，进而作用于选民的评价。