Supply and demand for truckers

Spending the morning at the NC State Poole College of Management's semi-annual Supply Chain Resource Cooperative meeting.  Lots of great student projects for companies like CAT, Duke Energy, GSK, MetLife and others.

One topic that has come up repeatedly is the shortage of truckers and the increasing difficulty firms are having with this critical transportation mode.  At the same time, the percentage of young people who are participating in the labor force is at a 30 year low.

So what is stopping young people (or even not so young) from entering the profession?  (I have posted on this topic before.) Lots of theories were offered.  Part of the story is that training is expensive to obtain (but there are student loans); another part is that many potential job candidates cannot pass background checks and drug tests (maybe, but I would like to see some numbers).  One new theory offered by Jason Schenker (economist and regular SCRC speaker) -- Xbox addiction.