The 18 Most Innovative Cities On Earth

Cities might be humanity's greatest invention - if you listen to Harvard economist Ed Glaeser, author of "Triumph of the City."

"So much of what humankind has achieved over the past three millennia has come out of the remarkable collaborative creations that come out of cities," he said in an interview. "We are a social species. We come out of the womb with the ability to sop up information from people around us. It's almost our defining characteristic as creatures. And cities play to that strength."

Indeed, many modern metros are pushing the limits of industry, design, and urban planning, while rethinking the way people live and work.

With that in mind, we assembled a list of the 18 most innovative cities in the world, using a range of metrics from patents per capita to skyscraper height.