In a short but interesting interview, Robin Nagle, a sanitation anthropologist studies what our trash says about us,

Q: What are some surprising things you’ve learned by analyzing garbage??

A: In affluent neighborhoods, I was profoundly impressed with how much good stuff rich people throw away.

via Trash is Her Treasure: Scientific American.

I guess I would rephrase that: she is impressed by how much stuff we buy in the first place that we don’t need.