Misery is not Miserly: Sad and Self-Focused Individuals Spend More (PDF; 236 KB)
Source: Society for Personality and Social Psychology (annual meeting)
From press release (National Science Foundation):

Off to buy a new handbag and fabulous red shoes, or how about overalls and a riding lawnmower? Before going, a mood check for signs of despair and gloom might be in order because how a person feels can impact routine economic transactions, whether he or she is aware of it or not.

So says a team of behavioral scientists from four major U.S. universities, whose research study finds that sadness impacts spending. Specifically, people who feel sad and self-focused pay more money for goods than those in neutral states, even when purchasing the same item.

“The tendency is to focus on oneself when sad drives this effect,” says the study’s lead author Cynthia E. Cryder, a doctoral student at Carnegie Mellon University, Pittsburgh, Pa. “Our studies revealed the more self-focused people were in the sad condition, the more money they spent.”

Docuticker