Here's an example of sports crowding out other economic activity*:

The renowned Vienna State Opera canceled one performance and complained about dismal attendance at another, blaming the European soccer championship being played in the Austrian capital.

Performances are usually nearly sold out, but the opera house said 29 percent of its seats went unsold for its most recent event, Verdi's "La forza del destino." The opera house also said it had decided to cancel a ballet evening June 29, the day when the final is played in Vienna.

Officials said in a statement Tuesday that would-be visitors fear negotiating through masses of soccer fans in downtown Vienna.

I'm betting that if an economic impact study of the European soccer tournament was done it didn't net out lower opera attendance and canceled opera performances.

*I think this idea is attributed to Phil Porter.