There continues to be noise from both sides, both sides, about why it is that we have more than traditional Full Employment, ~4.1%, yet wages/incomes have barely moved up since the Great Recession. Orange Julius Caesar brayed during the election that the issue was that Obama/BLS were lying, and the "real" employment rate was much, much higher; 42% was his favorite. No one who has a brain believed that. But doubting the truth of U3 is valid.
But the fact is, BLS has always published various versions (with various definitions, naturally) of the unemployment rate. The one labeled U3 is the "official" rate over the years. But that rate doesn't include folks who would be looking for new/better full time employment if they thought it mattered. Including those folks, and other marginally attached workers, makes for U6. You can play with the display.
The current U6 unemployment rate as of December 2017 is 8.10.
So, for the first time in history, Orange Julius Caesar is sort of right. The slack manifest in such a much larger U6 is why "full employment" U3 doesn't drive wage/income increase. The Right Wingnut Leona Helmsley Memorial Tax Cut for the 1% won't trickle down to drive up wages. There is zero historical evidence that such will happen.