Cities offer opportunity at the extreme end of the spectrum due to the concentration of people offering scalability. A professional spots team in the city, for example, can attract tens of thousands of paying spectators. "Field of Dreams" might attract a half dozen spectators on a good night. That's the difference between making millions and not being able to put food on the table.

But for the average Joe who will never leverage themselves into those extremes, I'm not sure the data actually shows greater opportunity. My read from the data is the average Joe is generally worse off in the city with respect to job prospects and compensation.