I'm writing a futuristic sci-fi story that takes place in a mostly post-scarcity economy. Resources are abundant, and no one needs to work for basic necessities or luxuries. Robots do all manual labor, and humans are free to spend their time on whatever they find interesting, whether it be scientific research, creating art, or just lounging around like a bum.
That being said, the one scarcity in my world is life force. The population is capped, and the only way for a new human to come into the world is for someone else to die. There is a waiting list for people to inherit the life force of the next person who dies, so that they can become parents (or hoard the life force for their future use). Some people are more desperate to have children than others, but the waiting list has become an unofficial monetary system for society, since it is the only scarcity.
I'm having trouble determining how this would work, though. My first thought was that people could trade positions on the waiting list for specialized goods and services, but that adds a bit of complexity, because what if the person who wants something is lower on the waiting list than the person providing the service? Could they just not "buy" anything from anyone above them?
My next thought was a point system where people would trade points for goods and services, and move up and down the list based on how many points they have. My issue with this though, is what happens once someone dies, and the top person receives their "payout". They would receive their "life force" and immediately go from being the richest person in the world to the poorest.
As I keep trying to figure out how this system would work, I keep running into new walls, and I need help understanding if this system is even possible and how.
So, can a waiting list be used as a monetary system? If not, what are the reasons? If so, what would be the best way to enforce it?
Side note: The humans in my story are pretty much immortal, and only die in freak accidents or by request. Death is uncommon, but does happen from time to time as people decide they are ready to move on (once every few years). I only say this, because it will probably impact the way people think about this system.
Edit 1: There are still services and specialized goods (i.e. art), that cannot be created by robots. For example, robots could build any house you want from the ground up, but you may want someone who's really good at designing houses to help you design it. People aren't inherently altruistic in this society, so they would seek some sort of payment in order to provide this service.
Edit 2: There is a council of "elders" who oversee most legal affairs. They would likely be the ones to oversee the list and resolve any disputes related to it.