Alan Krueger delivered the Martin Feldstein Lecture at the National Bureau of Economic Research this summer.  His lecture addressed the question: “How tight is the labor market?” Professor Krueger provided evidence that the long-term unemployed are increasingly leaving the labor force, and unlikely to return.  He further showed that the rate of real wage growth in recent months is consistent with a tightening labor market. 

A copy of the slides from his lecture is available here “How tight is the labor market?”
Video: NBER Feldstein Lecture by Alan Krueger on Labor Force Participation