COLUMBIA, S.C. (WSPA)—The NAACP announced Friday an economic boycott of North Carolina, urging organizers of religious conferences, sporting events, and concerts to go elsewhere. The NAACP cited the state’s law limiting LGBT protections and fights over voting rights as reasons for the boycott.

The civil rights group had a similar economic boycott of South Carolina that lasted more than 15 years because the state flew the Confederate flag at the Statehouse. It ended the boycott after the state removed the flag in July 2015.

Tom Regan, who teaches Sport and Entertainment Management at the University of South Carolina, studies the economic impact of sporting and entertainment events. He says it’s hard to estimate how much the boycott cost South Carolina. “It’s one of those situations where the money wasn’t spent, so how would you ever measure it?” he says.

But he says you can get some idea based on what South Carolina is now getting because the boycott is over. The SEC Women’s Basketball Tournament will be held in Greenville, and he says it’s expected to bring in $1 million to $1.2 million. If you extrapolate that to the length of the boycott, South Carolina may have lost close to $20 million.

“There’s no doubt that outside spending within South Carolina because of that (boycott) was down. Did it hurt our economy? I rather doubt that that $20 million made a bit of a difference one way or another to a hotel or eating and drinking establishment staying in business in South Carolina,” he says.

For most of the boycott, the NCAA would not allow any pre-determined sporting events to be held in South Carolina, things like conference tournaments and regionals. However, events earned on merit, like college baseball regionals and super-regionals, were allowed.

Regan says North Carolina’s loss should be South Carolina’s gain, since tournaments that would have been held in North Carolina might now come to South Carolina. And it’s not just sports.

“We’re going to have a better opportunity to get much better talent and concerts that may have bypassed us in the past, so that’s a real benefit, and, again, that’ll attract outside money and new money but also keeps the venues much busier,” he says.

“Is it detrimental to North Carolina? Probably overall. Is it a huge impact that’s going to cause decrease in employment or taxation issues? Probably not,” he says.