If you have any delusions that the use of public money to build stadiums or host sporting events provides an economic benefit to a city or country, please take a couple of minutes to read these articles about the burning dumpster fire that is Rio de Janeiro and the Summer Olympics.
"Rio de Janeiro governor declares state of financial emergency ahead of Olympics" The Guardian (6/17/16)
"As the Olympics near. Brazil and Rio let the bad times roll," New York Times (6/25/16)
"Rio visitors greeted with 'Welcome to Hell' banner," Yahoo Sports (6/28/16)
The only folks who claim that hosting these types of events and building fancy new playgrounds for fat cat owners are the owners themselves, the organizers of the games, league officials and every local politician who has his or her hand in the fire.
As I have stated before, if these really were money-making propositions, there would be no shortage of investors willing to pony up the bucks to make them happen. The very fact that state and local governments end up picking up the tab for these expenses tells you all you need to know about whether or not they are economic engines.