As early voting got underway with long lines in Georgia on Monday, NBC News reported that studies show race to be among the strongest factors predicting how long voters wait in line to cast their ballots.

In 2019, researchers from the University of California, Los Angeles, Carnegie Mellon University and the University of Chicago used smartphone data to quantify the racial disparity in waiting times at polls across the country. Residents of entirely-black neighborhoods waited 29 percent longer to vote and were 74 percent more likely to spend more than 30 minutes voting.

Similarly, nonwhite voters are seven times more likely than white voters to wait in line for more than an hour to vote, according to a 2017 study by the University of Pennsylvania’s Stephen Pettigrew, who is a senior analyst for the NBC News Decision Desk. The reason, the study concluded, is because election officials send more resources to white polling precincts.

Pettigrew told NBC News that long lines are more than a nuisance:

“Waiting in a line makes you less likely to turn out in subsequent elections,” Pettigrew said earlier this year, citing his research on that issue.

Read the full report.