The mean or average is a different animal than the median, yet the two are sometimes confused.  The median is the middle of a data set – 50% of the data are below that middle, 50% are above.  The median housing price for an area is more representative of the area than the average price, which is skewed higher by really expensive homes.

A revealing look at an overall trend in wages is the following table from the Social Security Administration, showing the growing disparity between the median wage and the average wage for the past two decades.  Adjusting for inflation, the median wage, in 1990 dollars, has increased 11% from $14,498 to $16,095 ($26,514 in 2008 dollars).  The average wage, however, has increased 19% – from $20,172 to $24,071 ($39,652 in 2008 dollars).  In the far right column of the table, we can see the ratio of median to average wage declining, showing that the top half of income earners are seeing significantly better progress than the lower half.

Stock market wags repeat the mantra that a rising tide raises all boats.  The tide of the past two decades has left half of the boats stuck in the mud.