This isn't really true always, the stadiums are "sold" (occupying teams threaten to move away) to cities and municipalities as economic engines...but truth is that football stadiums have little to no long term impact on job creation due to the fact that there are simply not enough games. Thats why the multi-stadiums were born in the 70s. It just doesn't work. The cities/taxpayers foot the bill with the team chipping in a bitty portion. But the real onus falls on Tax payer Joe gets who no monetary return, but a quality of life return if he happens to enjoy football. WNY/NY/Erie county can't afford a Allianze/ATT/Mercedes dome. If, er...WHEN buffalo gets a team it will look like Heinze Field or Lincoln Financial or Gillette.
(See Michael Leeds books about this)