The the cost of goods rises, people look for substitutes. So do my cats. Recently, I moved one of the litter boxes from the third floor to the first, where the other litter box is. (Each cat has its own litterbox.) Annoyed at the new, higher cost of usage (“I have to go all the way down there to pee?”) the cat procured a substitute: a persian rug.
Litterboxes, apparently, are positional goods. How do I know? The other cat, annoyed that her rival had a “new” litter box (i.e., the rug), decided to keep up with the Joneses and began peeing on the persian rug, too.
Felis silvestris economicus.