They did a study that showed the Canada could support x more teams in different sports, wonder if any feasibility study has been done for Chicago.
Intangibles would simply be would anyone actually desert the current team in a sport here to be a fan of another, or would they at least follow the new team assuming they were in another league?
Cubs-White Sox has gone back a long way, before fan bases were quite as established. In the then-growing city of Chicago, you had the NL's first dynasty in the Cubs (as they were called by 1903), winning pennants in 1876, 1880, 1881, 1882, 1885, and 1886, but nothing since. Then you had the White Sox who had won the AL pennant in the AL's first season as a major league. The Cubs were founded on October 12, 1869 just because the Excelsiors sucked compared to the top teams in New York and Brooklyn and of course Cincinnati in 1869... the city wanted a winner, and that is how the Sox were able to get into the market. But now times have changed, with more cemented allegiances, so it is questionable whether a new team would be able to gather fans efficiently enough here. My gut tells me it would work, but it would still be risky trying to put a 2nd NFL, NBA, or NHL team here (think NFL would work best given limited # of games and seats by the Bears).