Why, in that case, have average wages stagnated for so long?

We repeatedly read that the wages of regular employees are stagnating.

That's why wages, relative to inflation, have stagnated since the early 1970's.

And while more people may be working, inflation-adjusted wages are stagnating.

In the 1970s Poland's government raised food prices while wages stagnated.

Over recent years, wages have stagnated, and even gone backwards.

It plays to economic fears of workers whose wages have stagnated for two decades.

"From 1973 to the present, wages either declined or stagnated."

The typical benefit package has expanded little, if at all, in recent years, and real wages have stagnated.

But immigration has not been a major reason that wages at the bottom have stagnated for more than two decades.