Preliminary and incomplete.

Scholars make causal claims about the vote-boosting power of laws designed to increase turnout, citing evidence from regression analyses that show that generous voting laws are related to high turnout. Yet one must be skeptical of contamination from endogeneity in this relationship. The skeptic’s argument is: states with a culture of participation pass legislation designed to encourage voting. With participatory states being the cause of pro-turnout legislation, the causal direction is reversed from what is normally supposed. We take the skeptic’s argument seriously and use sensitivity tests to evaluate claims that turnout is influenced by pro-turnout legislation (and vise versa). Specifically, we apply a “zero covariance restrictions ” assumption and estimate the effect of turnout on legislation via two-stage least squares, with state demographic variables as instruments. Then, assuming that there are no unobserved variables that affect both turnout and legislation, we can back out the reverse effect of legislation on the vote. The 2SLS analysis shows that the turnout-legislation effect fully accounts for the turnout-legislation covariance, leaving no room for legislation to effect turnout