Explaining the Oil Advantage : Effects of Natural Resource Wealth on Incumbent Reelection in Iran

Why does natural resource wealth prolong incumbency? Using evidence from parliamentary elections in the Islamic Republic of Iran, I show that natural resource revenues boost incumbent reelection rates because this revenue is used to provide public or private goods to constituents, incentivizing voters to reelect incumbents over challengers. To test this hypothesis, I employ originally assembled data on five parliamentary elections in Iran (1992-2008) in longitudinal hierarchical regression analysis at the district and province level. By leveraging Iran's mixed-member electoral system, I am able to show that the resource-incumbency mechanism works primarily in single-member districts with little evidence of an incumbency advantage for politicians in resource-rich multi-member districts. Building on the rentier theory of natural resource wealth, my results suggest that voting for the incumbent is attributable to patronage and public goods distribution. My findings offer new insights into the understudied context of Iranian legislative elections, illustrate the mechanisms driving the relationship between resource wealth and incumbency advantage at the sub-national level in a non-democratic setting, and highlight the mediating effects of electoral institutions on the resource-incumbency relationship