Reports of labor shortages may not end anytime soon because a hefty number of retirement age workers have left the labor force - and a whole lot of them may not be coming back. A Friday note from Goldman Sachs researchers led by Jan Hatzius finds that 3.4 million of the people who left the labor force - meaning they're not working or aren't actively looking for work - are over 55. Roughly 1.5 million of them were early retirements, and 1 million were normal retirements. Those two groups of retirements "likely won't reverse," meaning that, out of the five...