Trust me, I have thought about that. I had a discussion about that very matter with my wife last night. I have no expertise in that field, so I couldn't do the economic analysis. I also have the sense that as hard as it is to predict the spread of a global pandemic, predicting the future of the economy is way tougher.
Here is what I can say for sure: I teach at The U of Iowa, and making the decision to transition to a virtual learning environment for the rest of the semester is a no-brainer. We are set up to do this already (we already offer a ton of online learning). It is a drastic change to do ALL of our instruction this way, but we can still accomplish our objectives. We still work, students still learn, and the in the meanwhile we eliminate tons of interpersonal contacts (assuming most students actually leave campus, which I think they will).
I feel like keeping fans away from these big events is equally a no-brainer. Especially considering that ticket sales is probably dwarfed by sale of broadcast rights? (not sure about that, but it seems right). But you are right, cancelling the event, and the money it brings in, will have a huge impact on the NCAA.
If the NBA cancels its season, that will have a huge impact on the financials of that league, which will trickle down to things like salary-cap and personnel-decisions.
But those are still small industries (the combined sports-for-entertainment industry across all sports is only about as big as the cardboard box industry in this country, factoid from Freakonomics).
As you have brought up, what about the potential crushing effects on small businesses, which are currently doing pretty well, but could be wiped out? Probably no bail outs for small businesses.
What about service industries?
The measures are not without their own costs. We will see.
