Chicago is at the center of a nation dedicated to innovation, “but something has been missing,” says Groupon co-founder Brad Keywell, in a report in the New York Times. Determined to fill the void, Mr. Keywell and his business partner Eric Lefkofsky founded a not-for-profit conference to be what Keywell calls “a platform for world-class ideas,” similar to the annual TED conference in California or the World Economic Forum in Davos, Switzerland.

However, unlike those two high-priced, high-minded gatherings, Mr. Keywell’s get-together, Chicago Ideas Week, is designed to be accessible to anyone with the time to attend—and at least $15 to spare. The second annual conference, a weeklong event, started Monday.

The event has seemingly earned some cachet. Chicago Mayor Rahm Emanuel signed on as a co-chair.  Journalist Tom Brokaw, AOL co-founder Steve Case, author Deepak Chopra, designer Diane von Furstenberg, retired Gen. Colin Powell, and actor Edward Norton are among the speakers. So far, 19,000 tickets have been sold.

“On Day One, I set it up as a nonprofit. I made a pledge to never make a penny off it,” Mr. Keywell said. “The motives are to have something that provides intellectual stimulation and provocation.”