I learned this from a bunch of long-term sailors who've cruised the world for many years, often with little or no savings at all. When the "cruising kitty" gets low they stop somewhere for a few months and work 'til it's built up again. The way they avoid spending extra money while they're ashore is to think of the money as "freedom chips", and when they've accumulated enough chips they cast off the lines again.
I've called them "freedom chits", I've heard "fun tickets"...AFAIAC they're as learned a definition as any economist will give!
One of my favorite money quotes-
"The only security men can have for their political liberty, consists in keeping their money in their own pockets"- Lysander Spooner