The Statistical Role in Voter Identification (ID) Laws

Abstract

Many public policy issues have at their core statistical issues. It is extremely important that these issues be addressed by statisticians, and their findings must be explained to the public, legislators, and judges. The recent Voter Identification bills passed by a number of state legislatures are a case in point. This article summarizes the statistical issues at the heart of the recent court case between the State of Texas and the Federal government over the Voter ID legislation passed in that state. The Federal court ruled that, “all of Texas's evidence… is some combination of invalid, irrelevant, and unreliable.”

KEY WORDS::

• Response rate
• Statistical matching
• Weighting

Notes

I testified as an expert witness on behalf of the Texas State Conference of the NAACP Branches and the Mexican American Legislative Caucus of the Texas House of Representatives, intervenors on behalf of the Federal government.

After Dr. Ansolabehere conducted his matching, Dr. Shaw conducted a second set of surveys based on this revised database. These had similar results and quality although only unweighted results were presented to the court. This article only discusses the findings from the initial two surveys.