Retired investors should be aware that the cost of living, measured as the Consumer Price Index,
will match the appreciation of the stock market, as measured by the Dow Jones Industrial Average Index.
As the consequence, seniors must keep their investment savings always earning returns that exceed stock price indexes.
Source for CPI: http://www.bls.gov/regions/mid-atlantic/data/consumerpriceindexhistorical_northeast_table.htm
Source for DJI: https://research.stlouisfed.org/fred2/series/DJIA#