I was reading how the median income has shrunk since 2000.  In the piece the author revealed that productivity by labor had increased 60% from 1979.  I also read how savings rates were 10% in the 1980's, 5% in the 90's and NEGATIVE in the 2000's... so can I put all three together to find anything?

Here is my thesis: Income shrinks as savings evaporate and turn negative.  First of all savings/investments earn money.  So for example if your savings has a 3% interest rate that adds on to your income.  If you withdraw from your savings you stop gaining that interest that you had in the 80s and 90s.  If you overdraw then guess what?  Your income shrinks.  Your wages might not shrink - but you're losing interest that you would have gained... hence a decrease in median income.

Production has gone up but world demand has gone up too.  Inflation has not been a problem since the 70's but if anyone has some good cost of living numbers let me know.