Q and O has several pieces covering this but my favorite is by Dale Franks who points out that:
Additionally, 141,865,000 people were employed in April, down from 142,034,000 in March, a decline of 169,000 in the number of people employed.So with fewer people actually having jobs, the unemployment rate goes down because more people who were looking, and thus were counted as unemployed, have simply given up, and thus are now simply not counted.
Remember, when workforce participation reached 58% or so, unemployment will be zero.
It is worth noting that it's not retiring boomers that are driving this dropout rate either, in fact the 55 and up demographic is actually going back to work. It's the younger groups that are taking it in the shorts.
Going back to Dale:
As always, I’d point out that, if the labor force participation rate were at the historical average of 66.2%, the actual unemployment rate for April would be 11.73%, up from 11.56% in March.This is the new math. You won't see a resurgence of the old math until a Republican gets elected.