http://enough.enviroweb.org/enough08.htm
"Any relation that does exist
between happiness and
income is relative rather than
absolute. the happiness
people derive from
consumption is based on
whether they consume more
than their neighbours and
more than they did in the past.
The upper classes in any
society are more satisfied with
their lives than the lower
classes are, but they are no
more satisfied than the upper
classes of much poorer
countries, nor than the upper
classes were in the less
affluent past."
Michael Argyle, The
psychology of happiness