good article that has lots of researched facts, numbers and jumping off points to studies done on possessions and happiness, proper researched facts, also talks about a book I've looked into that I think we could get some good quotes from - The Theory of the Leisure Class, it was written in 1899. Basically they guy claims that consumerism or the pursuit of high class, "irrational creatures who pursue social status with little regard to their own happiness."

article here
The Theory of the Leisure Class - wikipedia version
The book