From the Daily Galaxy:
Researchers have found that low self-esteem and materialism are not just a correlation, but also a causal relationship where low self esteem increases materialism, and materialism can also create low self-esteem. They also found that as self esteem increases, materialism decreases. The study primarily focused on how this relationship affects children and adolescents. Lan Nguyen Chaplin (University of Illinois Urbana-Champaign) and Deborah Roedder John (University of Minnesota) found that even a simple gesture to raise self-esteem dramatically decreased materialism, which provides a way to cope with insecurity.
Poor self esteem -> More stuff -> Worse self-esteem -> Even More stuff -> Even worse self-esteem -> Lots and lots more stuff -> Continue
This can't end well.