Is there a way to estimate how much scalping is actually playing into box office numbers?

Like people have reported trying to buy tickets for opening weekends only to find that the scalper in front of them bought 10 tickets at once. If that is a nationwide trend, it would make perfect sense that the box office is huge but the actual numbers of filled seats and ticket buyers is a lot lower. Is there any effort to discern the effect the scalpers are having on inflating the numbers?