How can a median wage drop 4% for a portion of a population? What am I missing here?
You can compute the median wage for Blacks, Catholics, Left-handed Lesbian Windshield Installers, or any other identifiable group, for which the pertinent records are kept.
The bottom 80% of the population is just another group.
The median wage of just about any group will change over time. Unfortunately, for the bottom 80% of the population, it went down 4% from 1999 to 2003, in real, inflation-adjusted terms. This while the total economy is growing nicely.
This should not be a Democrat/Republican, liberal/conservative, scream and yell, pointing fingers blame game.
There is something, or some effect, in the economy, that is screwing over the middle-class, and, whatever it is, we need to identify it, and clip it in the bud, before our middle class gets a nice taste of Mexican peonage. (Shoot, maybe that IS the idea.)
Coladirienzi is correct. You can measure median income for any group. I don't know that I believe his assertion. And anytime you look at a period including a recession, chances are there is a drop in median income. I'd have to look at the data. Perhaps coladirienzi has a link?