"The denomination in which money is held influences consumer spending," write the authors, from University of Iowa. They term the propensity to hold a single bill in higher regard "a bias for the whole."
This single value also gives large bills something the authors call "processing fluency": "A single bill possesses Gestalt features of cohesion and economy that multiple bills lack," the authors explain.
In an attempt to better understand how processing fluency affects the pleasurable qualities of large bills, the authors designed a study aimed at improving the perceived value of smaller bills. Participants had to imagine putting geometric shapes together to make a larger, more interesting shape. They were then given small bills and asked how willingly they would buy things with this newfound money.
As the researchers predicted, this exercise decreased the participants' willingness to part with smaller bills, as they would correlated the value to a larger bill.
"It appears that money is not just regarded as a medium of exchange but as an object of evaluation in its own right," write the authors.
Himanshu Mishra, Arul Mishra, and Dhananjay Nayakankuppam. "Money: A Bias for the Whole." Journal of Consumer Research. March 2006.