A new report raises questions about the effectiveness of strict voter ID laws in deterring election fraud.
It also argues the laws do not disenfranchise some groups of voters, as opponents often claim.
In the paper published by Vincent Pons, of the Harvard University Business School, and Enrico Cantoni, of the University of Bologna, the authors conclude there is "no significant, negative effect on registration or turnout" caused by voter ID laws in 11 states deemed to be strict.
The paper added the trend holds "overall, or for any subgroup defined by age, gender, race or party affiliation."
The authors also write that strict voter ID laws had "no significant impact on fraud or public confidence in election integrity," according to statistics.
The researchers analyzed statistics from political data vendor Catalist.
Those numbers included the "vast majority of the U.S. voting-eligible population in the 2008, 2010, 2012, 2014, and 2016 general elections, resulting in about 1.3 billion observations."
Pons said the Catalist data enabled him and Cantoni to analyze trends among voting-age people both registered and unregistered, and even track their behavior if they moved across state lines.
In compiling data on reported cases of voter fraud, the authors examined statistics from the conservative Heritage Foundation and News 21, which they describe as "a more liberal initiative."
"Our hope was to bring empirical evidence to the debate," said Pons.
In summarizing his findings, Pons said, "if you're concerned about low participation, your concerns might be better targeted toward other areas of improvement. For instance, making registration easier, or increasing the density of polling stations to decrease travel time to the polls."
"And if you're worried about the low trust some Americans have in elections, again, there might be better things for you to target your efforts on, such as improving the state of technology they use at polling stations," Pons added.
In Milwaukee, Neil Albrecht, the executive director of the city's Election Commission, said officials spent between $80,000 and $100,000 to implement the state's voter ID law.
He said the bulk of those expenses were training poll workers. But the cost also covered public information campaigns through billboards, flyers and mailings.
"And if you're worried about the low trust some Americans have in elections, again, there might be better things for you to target your efforts on, such as improving the state of technology they use at polling stations." -- Vincent Pons, Harvard professor and co-author of paper
Albrecht said he agrees with Pons' finding that voter ID wasn't necessary to prevent fraud, as he argues there wasn't a significant level of voter fraud in Milwaukee to begin with.
"In Wisconsin, we're a swing state," Albrecht said. "We have some of the most scrutinized elections in the country. We're under a microscope for fraud."
But Albrecht said he disagrees with the theory that strict voter ID laws, such as Wisconsin's, haven't suppressed turnout among some voting groups.
He said recent elections have shown an increase in new voters in areas of the city such as Downtown and Bay View.
"But when we look at areas of the city where we have the highest concentration of people in poverty, we saw really significant decreases in voting," Albrecht said.
He argues that's due to the state's voter ID requirement.
"This is a pattern we're consistently seeing since the photo ID law came into effect," Albrecht said.
In their recent publication, Pons and Cantoni conclude by writing, "because states adopted strict ID laws only 2 to 12 years ago, our results should be interpreted with caution: we find negative participation effects neither in the first election after the adoption of the laws nor in following ones, but cannot rule out that such effects will arise in the future."
"Enforcement of the laws already varies across locations and could very well become more stringent over time, especially if polarization on the issue increases," the authors said.