I don't have any authoritative figures off-hand, and I too have no use for organized sports. I've never been impressed with what organized sports contribute to a community, though. When the Mariners threatened to leave Seattle because they wanted a new stadium, a vote was put before King County voters, and it was defeated. And so instead, the state Legislature stepped in and found a way to fund it with public money. They pretty much ignored the will of the people and did an end-run around them. I have no information the resulting economic impact. The stadium isn't in a residential part of town, but I don't think it's slummy. Whether or not that has anything to do with the stadiums, though, I don't know.

I'm more familiar with the effect of sports at the collegiate level. At UT-Austin, a whole lot of effort and money went into the sports program there, but very little came out. I remember the sports programs were uniquely exempted from requirements to share money with the University at large -- unlike the rest of the campus, who had to fork over some of their hard-earned grants to the university.

I'll be interested to see if you turn up any hard data on this.