The obvious conclusion that nobody but you has reached?
In an economy the size of Cleveland, almost anything can have an economic impact in the hundreds of thousands. But it's not always easy to see what that impact is. One could argue, for example, that The Decision played a role in how long it took the terrible post-LeBron team to break the sell-out streak. Maybe the fans made an extra effort to make it to games to show up LeBron, let him know what he'd left. Maybe the sell-out streak would have ended 5 games earlier, maybe over the course of the season The Decision sold 10,000 extra tickets. Then those fans buy food and beer in the surrounding area, buy Cavs gear, etc. I don't think you can just offhand say, "something bad happened to people, so they spent less money" as if that were a foregone conclusion. If something bad happens to them economically, obviously. But The Decision isn't economic, it's a social occurrence, and I think your giant assumption that this would "obviously" cause people to spend less money is short-sighted.