What is worth more, a degree in art, or a certificate in plumbing?

Have you ever seen the insides of a factory or a refinery? Have you been told that you must go to college in order to have a good paying job? Joel Kotkin is the most knowledgeable writer I know of when it comes to geography and economy. He writes here about the regions of the country where high paying working class jobs are on the upswing. The top three? Houston, Oklahoma City, and Detroit! Yes, that Detroit, where US auto companies are coming back.