Stadiums economic impact

What have economists discovered when looking for benefits related to stadium subsidies? Are you surprised at the results of their analysis? Why do municipalities continue to fund these projects in spite of the lack of benefits? Do you anticipate support for these projects to erode in the future? Compare the subsidies for local sport teams to those for mega-sporting events (Olympics, World Cup, etc.). Would you anticipate economists finding economic rationale for these? Why or why not?