Beneath the surface, unnoticed by many, an even deeper force was at work—the rise of creativity as a fundamental economic driver, and the rise of a new social class, the Creative Class.

Places that succeed in attracting and retaining creative class people prosper; those that fail don't.

Builders need to take their preeminent position back from the traders for the economy of the future to flourish.

Already, new forms of short-term and long-term rental housing are popping up in some metro areas. You can take on a house or apartment for a few months or even a year or two in developments that are striving to provide critical elements of community - schools, healthcare, social and cultural institutions - even for people who are living there only temporarily. People invested in a home, mortgage, or community are less likely to move to more economically vibrant locales. That kind of entrenchment is going to be an impediment to the coming spatial fix.

Denser cities are smarter and more productive

We are the only major developed nation that isn't investing meaningfully in high-speed rail, and I believe we're making a mistake. Transportation systems that are fast and efficient and environmentally clean are going to enable the formation of these new mega-regions, the heart of the spatial fix. We need to be able to accelerate the movement of people, goods, and services - the very movement of ideas, knowledge, and creativity - between our major population centers. We have to build these links.

We have to acknowledge that we can't look to manufacturing or natural resources to drive growth like we have in the past. Human capital, talent, and knowledge are our most important resources now. Every city has hidden seeds of opportunity waiting to be nurtured. Places like Detroit, Cleveland, and Pittsburgh are among my favorite cities. They have great universities, clusters of innovation across a range of industries, and pools of innovative and creative talent to build on.