The data seems to indicate that a sharp decline in Real Median Personal Income to a negative growth year over year seems to precede an economic recession.
As for the causes of this correlation, one might well wonder. But given that the US economy tends to be consumption driven, a sharp decline in real median personal income would seem to be something worth considering.
And one might well ask, are we headed for that same experience today, with a broad slowing in aggregate demand because of a decline in growth of median income?
Below this I also include a chart that shows the growth of average hourly wages of non-supervisory workers. I looked this up because of a minor debate going on between two popular media economists, Baker and Krugman, about the start of wage stagnation, whether it has been since 1980, or the last recession.
As always it seems, I was not able to find my exact desired data, which would have been median real wage growth in non-supervisory, non-salaried workers. But the case for 1980 as the start of stagnation seems rather good.
But I did stumble upon this phenomenon of declining personal income preceding recessions, which seems much more important, if true. So it was not a complete waste of time to pursue this quibble over whether we are at full employment now, and why wage growth is not yet appearing.