Link here to article
This article focuses on the economic impact for the area that's hosting the game. In theory, the area hosting the game could see a positive economic impact if it draws in visitors it otherwise wouldn't have.
What about the US as a whole? For the US the economic impact of the Super Bowl is close to zero. Many people will spend significant amounts of money on travel, tickets, etc. Others will spend lesser amounts on food items for parties and souvenirs. Each dollar spent is one dollar less to spend elsewhere, however, so the overall impact to the economy is negligible.