Is Four Twice as Nice as Two? A Natural Experiment on the Electoral Effects of Legislative Term Length

In Illinois and Texas, senate elections return members to serve terms of different length. Because term length schedules are randomized, these states provide a natural experiment. Cross-sectional comparison of chambers requires statistical controls for myriad factors that distinguish cases (chambers or periods). These two chambers, by contrast, produce direct evidence of term length’s impact on electoral behavior. We test hypotheses about term length’s impact on candidacies, campaign expenditures, and voter participation with data from 1968 to 2010. Surprisingly, there is little evidence of any significant differences between contests for two-year and four-year terms.