A note on electoral competition and turnout in run-off electoral systems: Taking into account both endogeneity and attenuation bias

In this short note, I propose an identification strategy to estimate the causal effect of expected electoral competition on voter turnout in run-off systems taking into account both endogeneity and attenuation bias. I find that electoral competition significantly raises turnout. Not addressing attenuation bias yields estimates that are biased by up to 50%.