With the unemployment rate in America hovering around 3.9% -- well below the 5.2% to 6% considered "full employment" -- it has become harder for companies to fill open positions. That has in some cases pushed wages higher, and it has forced a number of large-scale employers to offer improved benefits, including helping workers pay for college.And while the idea of "full employment" can be debated, there are currently 6.9 million job openings and 6.2 million unemployed workers, according to recent reports by the Bureau of Labor Statistics (BLS).