Voter ID law effects hard to pinpoint

Indiana's strict voter identification law may have prevented some elderly citizens from voting in the last two presidential elections, but there's little evidence it kept large numbers of voters from the polls, according to research by Indiana University Bloomington doctoral student Adam Nicholson.

Nicholson compared turnout figures in the 2000, 2004, 2008 and 2012 elections in Indiana and in Nebraska and Pennsylvania, two states without voter ID laws. Unlike most previous research on voter identification laws, the study examined data at the county level, not the state level.

"In counties with high populations of elderly voters, you actually see a decline overall in turnout," said Nicholson, who conducted the study as his IU master's thesis.

Indiana adopted a law in 2005 requiring residents to present a federal or state photo ID card in order to vote. The law was challenged, but the Supreme Court ruled it constitutional in 2008.

"After the Indiana law was upheld, it sort of opened the floodgates for other states," Nicholson said. According to the National Conference of State Legislatures, 32 states now have voter ID laws—including seven states with "strict" laws. Kansas, Nicholson's home state, enacted a voter ID law in 2011.

Nicholson compared Indiana with Nebraska and Pennsylvania because the states, while different in some regards, are similar in the number of counties and the population mix. Overall, voter turnout was somewhat low in 2000 and lower in 2004, and peaked in 2008. Turnout in Indiana counties was high in 2008 but declined more sharply than in other states in 2012.

Critics say voter ID laws discriminate against elderly, poor and minority voters. But Barack Obama's candidacy in 2008 and 2012 led to large turnout among black voters, according to previous studies. For that and other reasons, Nicholson said, it will take more elections to render a verdict on ID laws.

"Hopefully the work I'm doing is a push in the right direction and will give people an idea of how to approach it," he said. "More than anything, as time plays out, having more data points across multiple elections will be helpful."