well that all depends on the demographics/metrics you are talking about. For instance, for football restaurants might not see a big improvement in business, but I would have to think that the Kroger and Baeslers see a big sell on hotdogs, hamburger, buns, beer, etc. Because the tailgating is growingo on gamedays. Most people coming in from out of town won't necessarily bring the food with them...but I am guessing on that. but then basketball is different, I would think that bars and restaurants are or will see huge growth in sales especially places like the Terminal, Copper Bar, etc. and the hotels too, but during basketball.
Also, night games effect sales for the local businesses. If football games are at night you will probably see more hotel and restaurant spending in TH. But a football game that starts at 2 PM, most that attend will end up going back home and not ever really need to spend that much money other than maybe gas and a Dollar Menu hamburger on the way out of town potentially they might sit down and eat, but that adds another 2 hours onto the time someone from Indy might get home. So if they leave "quickly" after the game they might get home at 6 PM...but is someone from Indy stops and sits to eat they aren't getting home until 9-10 PM. Its a big difference.
You are right one time events like Homecoming, Pre-Nats, etc. are different. But the typical weekly games are the real question.