Darren Grant for Public Choice:

Primary and runoff elections in Texas provide an ideal test of the ballot order hypothesis, because ballot order is randomized within each county and the state offers many counties and contests to analyze. Doing so for all statewide offices contested in the 2014 Democratic and Republican primaries and runoffs yields precise estimates of the ballot order effect across 24 different contests, including several not studied previously. Except for a few high-profile, high-information races, the ballot order effect is large, especially in down-ballot races for judicial positions. There, the empirical results indicate that going from last to first on the ballot raises a candidate’s vote share by nearly ten percentage points. The magnitude of this effect is not sensitive to demographic and economic factors.