jnosCo

  "GAO compared turnout in two states—Kansas and Tennessee—that changed ID requirements from the 2008 to 2012 general elections with turnout in fourselected states—Alabama, Arkansas, Delaware, and Maine—that did not. GAO used a quasi-experimental approach, a type of policy evaluation that compares how an outcome changes over time in a treatment groupthat adopted a new policy, to a comparison group that did not make the same change. GAO selected states for evaluation that did not have other factors in their election environments that also may have affected turnout, such as significant changes to other election laws. GAO analyzed three sources of turnout data for the 2008 and 2012 general elections: (1) data on eligible voters, using official voter records compiled by the United States Elections Project at George Mason University, (2) data on registered voters, using state voter databases that were cleaned by a vendor through data-matching procedures to remove voters who had died or moved, and (3) data on registered voters, as reported to the Current Population Survey conducted by the U.S. Census Bureau. [...]