<<I find it VERY hard to believe that $12/hr delivery jobs are going begging.>>
Murray's statement also struck me as being so utterly absurd that you wonder if he's living on the same planet as everybody else. The statement is typical of the "ivory tower" syndrome that blinds academics to real-world realities
For people who are unemployed, finding any $12/hour job can be difficult. The $12 / hour jobs that are available may not be steady work. Companies tend to hire part-time contractors now, not full-time employees. There are former engineering professionals in my family who are working part-time odd jobs for $7.50 an hour. Professionals who have been out of work more than two years generally won't even be considered for employment. They feel as though they are living under an economic death sentence.
It is difficult to generalize because there are also people who have been unaffected by the recession. People who work in the tenured ranks of government or academia (as Murray does) or who have learned to represent themselves as self-employed entrepreneurs may be doing OK. I've noticed that people with secure jobs can't imagine why anyone would be unemployed. They think that jobs are there for the asking. But for people who are out of work and desperately need employment to support themselves and their families, the opportunities may be few and far between.
One thing that is pretty clear, though, is that for most people those "go to work out of college and retire with a golden watch" days of secure career employment are gone, long gone. That is why the middle class is shrinking.