: : the various displays of wealth (which after all are only meaningful as long as there exist a poor against which wealth can be measured)
: I would suggest that 'displays of wealth' are buying education, health, leisure time and generally looking after yourself and your loved ones. In this context they are not relavent only as compared to the poor - but as measured in quality of life
I don't think education or health would be considered by most people as a "display" of wealth. I was speaking more of the psychology of display itself - showing off.
As for leasure it depends. Roughly 30 percent of the world's population is unemployed (a good source for exploitation). They have plenty of "leisure", but I doubt they consider it a display of wealth.