Cities foster the communication of complex ideas, making them key to the future of America and the world, Economics Professor Edward L. Glaeser said yesterday in a talk at the Harvard Book Store.

Glaeser’s new book, “Triumph of a City,” explores the cultural and economic spheres of major cities today. His presentation yesterday focused on the ability of cities to enable people to communicate and share ideas in more valuable ways than telecommunication.

“It is remarkable that despite the radical decline in transportation and communication costs that cities remain so vital, important, and successful,” Glaeser said. “This is true in the United States, where cities have come roaring back from the troubled period of the 1970s, and it’s even more true in the developing world where cities are providing a path from poverty to prosperity,”

Glaeser also commented on the current state of the U.S. economy, particularly with regards to the recent mortgage crisis and persistent sprawl into the suburbs.

“As America looks forward to economic renewal it is not going to come from hiring lots of guys to put up infrastructure in low-density America, it’s going to come from being smarter. It’s going to come from outthinking other countries on the planet,” Glaeser said.

Glaeser, who teaches the course Economics 1011a: “Microeconomic Theory,” explained to the audience that cities serve the special purpose of providing people with the face-to-face contact that allows for human capital and productivity to increase. As human beings we are naturally a social species that has the innate ability to “sop up” information from those around them, and cities, he said, appeal to this very instinct.

Glaeser said that as much as teachers and professors would like to think that they are the most important source of imparting ideas, cities truly fulfill this function better than any teacher ever could.

Still, Glaeser added that schools provide one the vital centers of communication and that their improvement is essential for keeping urban populations high.

“There is no reason why cities can’t have uniformly good schools. The same powers of competition and innovation that work in the private sector can work for schools as well,” he said.

After appearing in multiple media outlets, Glaeser just returned to Cambridge after speaking on the Daily Show with John Stewart Monday night.

“I haven’t been that scared in 30 years. You’re in a position where it’s enormously easy to make both yourself and indeed Harvard look very foolish. I did my best to try and avoid that,” Glaeser said.

But in the end Glaeser said it was a good experience

“Stewart himself was enormously kind and a pleasure to work with—and he gave me a Daily Show t-shirt.”