The Olypmics are a loss for the host city/country.
The one big net...you're providing a lot of income/jobs for local workers. Construction, cleanup, painting, shopping, food, etc...all local joes...work that isn't outsourced to India, China, Thailand, Mexico, etc.
It DOES help the locals running businesses, but it's the city and the state that lose big time...and ultimately the government and the taxpayers.
Don't they have sales tax in Illinois? If so, then those local businesses are adding to the pockets of the government. And once again, it is the long term impact that has to be taken into account. There might be an immediate loss, but with all the improvements made in facilities and added attractions, I can see where the money would be made back plus.
The sucky of Chicago has a 10+% sales tax. HOWEVER, the local businesses and construction companies are going to make out FAR better than the city will having to drop millions upon millions in new stadiums, parking lots, etc. Consider the cost of having to refurb all the metro trains. How about generic cleaning? Massively enhanced staffing? Building parking garages, stadiums, visitors centers, etc? I don't see the city coming out ahead whatsoever.
Chicago is one of the absolutely worst cities to park in and commute. It's awful. The only nice thing, is commuting from the burbs (i.e Elburn, Aurora, Naperville, etc) and taking the train.
Chicago already has a bunch of parks that cost millions of dollars to build...and they're used like a few a times a year. Stadiums - there's no room to build anything downtown, without knocking down a half dozen buildings (millions and millions of bucks). Thus, they'd have to build it in the burbs or on the north or south sides of town. Not real attractive of options.
Did Beijing come out on the short end of the stick for the outrageous amount of wasted cash they forked out? I believe so.
The same would happen for Chicago.
If Chicago wants money - beg for the MLB All-Star game, the Superbowl, etc. Detroit made out pretty good during both. Outside of committing all police to simply be security and setting records of petty thefts, break ins and stolen cars, it worked out pretty well.