Quote:Moretti demonstrates that there really are two Americas -- one that's healthy, rich and growing, and a second that's increasingly being left behind. The two nations-within-a-nation are divided not so much by region or race or religion, but by the kinds of industries they support. Those cities and towns that are home to innovative industries -- information technology, pharmaceuticals, advanced manufacturing and the like -- are wealthier, healthier and safer, while the places without these industries are steadily declining.

"The New Geography of Jobs" catalogs these changes relentlessly. Moretti has done his homework -- he can rattle off the names of places like Visalia, California, and Bridgeton, New Jersey, that have failed to catch the train of the innovation economy. In graph after graph, he shows that the cities with better social indicators in the 1980s -- longer life expectancy, lower divorce rates and higher voter turnout -- have steadily increased their advantage since then.

And these are also the cities with the highest number of college graduates -- the innovation hubs. The places that are being left behind are the ones that lack top-end human capital. Why this divergence? The reason, Moretti explains, is what economists call local multipliers. Every American with a high-paying innovation job -- every software engineer, every manager at a drug company -- shops locally. They pay doctors to fix their knees. They pay yoga teachers and personal trainers and dieticians. They hire roofers and landscapers and electricians and plumbers. They shop at local stores and eat at local restaurants. Every dollar that the innovation industries pull in from outside gets spent around town, and then spent again.