Question
In which ways is the standard of living a function of population size?
Answer
At the lowest level, standard of living is simply species survivability, and I recall one excellent data point about that: the colonization of Australia by early humans. Back then the seas were lower and the water gap between SE Asia and Australia was smaller and I believe there is now evidence and work on the minimum size of the group needed for a high probability of survival.
It was apparently a very daring feat, because the ocean crossing, though shorter than it would be today, would still have been a huge leap into the unknown back then (40,000 BC of whatever it was... I forgot the links to the precise details).
Today, if you wanted a lower bound on a slightly more comfortable perpetuation of the species instead of a precarious ocean journey on rafts, you'd need to look at things like space colonies/Noah's Ark type thought experiments.
I'll interpret "standard of living" in today's consumerist terms: it is a strong correlate/function of the number of specialized products and services available to consume. A society with more such variety has a higher standard of living than one with fewer. This is obviously a politically-charged definition, and minimalists would claim if you just were enlightened, you could live with far fewer specialized things, but let's leave that debate aside.
The right mental model is to think in terms of degree of specialization required to produce any service/product in the production web. If some artifact or service requires 10 different specialists, at some point it will become unsustainable because you won't have the human resources to sustain those specialized functions. You cannot really budget half a modern doctor. You have to budget for a medical education system and at least a few doctors with critical mass to keep the profession vital and evolving. If you budget half a doctor in your little community, you'll get a witchdoctor/shaman/medicine man rather than a modern, scientifically educated MD.
So you'd have to refactor the production of things to the extent possible using more general-purpose human resources. At a sufficiently small scale for example, doctor and surgeon might collapse into one. Mechanical engineer and auto mechanic might collapse into one. Or you might have different sorts of weird consolidations and unsuspected clusterings in the refactoring. Maybe the s/w people will have to double as poets, which I think Ruby people at least could pull off. Maybe mechanical engineers don't collapse with auto mechanics but with cooks. Maybe surgeons have to serve as barbers too, as they once did.
But overall I think the lower bound to sustain standards would be MUCH smaller than people suspect, once you intelligently refactor the living standards and specialization needed. I conjecture we'd see a power law or something: you could get 80% of the standard of living with 20% of the current population.
The reason is that as you shrink the population, things that need to be done on an industrial scale can now be done on a home-business scale because demand also shrinks. At a scale of a 100 families for example, a single carpenter hand-building wooden furniture with hand tools is enough to replace the entire sophisticated wooden furniture manufacturing industry. You can get rid of the demand for all the specialized intermediary industrial products that are only needed beyond a certain scale.
If you wanted coffee, just a couple of guys growing a few bushes might be enough. Instead of the pharma industry, you might be able to get away with a few greenhouses worth of rare plants and meth-lab level infrastructure... which is what traditional medicine has always been, except that here you'd throw all the digitized medical knowledge you could at it.
But as you scale down, you'd have to make some hard choices. Below a certain scale for example, perhaps MRI machines become impossible. The stuff that basically falls out of the production web as you try to shrink its absolute size is going to be a fairly unpredictable set.
As I write this answer, it is becoming clear to me that the REAL question here is not population vs. sustainable standard of living (which will peak at some point as more human resources add consumption without adding production that improves standards).
The real question is population scale vs. degree of sustainable specialization (if you have 1000 people, perhaps you can have 10 professions)
You'd need to complement that with a sort of rank-ordering of specialized professions, in ontogenic order (mech engineers come before elec which in turn comes before CS, quite logical...). You could then plot number of professions vs. size of production web that can be sustained by that level of specialization. So maybe an economy with 34 professions can sustain a production web that produces 10,329 different types of products/services.
It was apparently a very daring feat, because the ocean crossing, though shorter than it would be today, would still have been a huge leap into the unknown back then (40,000 BC of whatever it was... I forgot the links to the precise details).
Today, if you wanted a lower bound on a slightly more comfortable perpetuation of the species instead of a precarious ocean journey on rafts, you'd need to look at things like space colonies/Noah's Ark type thought experiments.
I'll interpret "standard of living" in today's consumerist terms: it is a strong correlate/function of the number of specialized products and services available to consume. A society with more such variety has a higher standard of living than one with fewer. This is obviously a politically-charged definition, and minimalists would claim if you just were enlightened, you could live with far fewer specialized things, but let's leave that debate aside.
The right mental model is to think in terms of degree of specialization required to produce any service/product in the production web. If some artifact or service requires 10 different specialists, at some point it will become unsustainable because you won't have the human resources to sustain those specialized functions. You cannot really budget half a modern doctor. You have to budget for a medical education system and at least a few doctors with critical mass to keep the profession vital and evolving. If you budget half a doctor in your little community, you'll get a witchdoctor/shaman/medicine man rather than a modern, scientifically educated MD.
So you'd have to refactor the production of things to the extent possible using more general-purpose human resources. At a sufficiently small scale for example, doctor and surgeon might collapse into one. Mechanical engineer and auto mechanic might collapse into one. Or you might have different sorts of weird consolidations and unsuspected clusterings in the refactoring. Maybe the s/w people will have to double as poets, which I think Ruby people at least could pull off. Maybe mechanical engineers don't collapse with auto mechanics but with cooks. Maybe surgeons have to serve as barbers too, as they once did.
But overall I think the lower bound to sustain standards would be MUCH smaller than people suspect, once you intelligently refactor the living standards and specialization needed. I conjecture we'd see a power law or something: you could get 80% of the standard of living with 20% of the current population.
The reason is that as you shrink the population, things that need to be done on an industrial scale can now be done on a home-business scale because demand also shrinks. At a scale of a 100 families for example, a single carpenter hand-building wooden furniture with hand tools is enough to replace the entire sophisticated wooden furniture manufacturing industry. You can get rid of the demand for all the specialized intermediary industrial products that are only needed beyond a certain scale.
If you wanted coffee, just a couple of guys growing a few bushes might be enough. Instead of the pharma industry, you might be able to get away with a few greenhouses worth of rare plants and meth-lab level infrastructure... which is what traditional medicine has always been, except that here you'd throw all the digitized medical knowledge you could at it.
But as you scale down, you'd have to make some hard choices. Below a certain scale for example, perhaps MRI machines become impossible. The stuff that basically falls out of the production web as you try to shrink its absolute size is going to be a fairly unpredictable set.
As I write this answer, it is becoming clear to me that the REAL question here is not population vs. sustainable standard of living (which will peak at some point as more human resources add consumption without adding production that improves standards).
The real question is population scale vs. degree of sustainable specialization (if you have 1000 people, perhaps you can have 10 professions)
You'd need to complement that with a sort of rank-ordering of specialized professions, in ontogenic order (mech engineers come before elec which in turn comes before CS, quite logical...). You could then plot number of professions vs. size of production web that can be sustained by that level of specialization. So maybe an economy with 34 professions can sustain a production web that produces 10,329 different types of products/services.