The US per unit labor cost has gone up 20%, how is that possible given the economic crisis since late 2007? (Webinar Attendee Question)

This situation always occurs. Labor is a relatively constant expense in the short-run. The simple math is as follows - if labor costs are $100 and revenues are $1,000, the cost of labor is 10%. Now if the economy plunges and revenues fall to $500, the labor costs go to 20%. You can modify the equation with unit costs and margins, but the math will be similar.