Population needed for technology levels.

[kato13]

The ammo reloading thread has brought this thought into my head once again. We all know that agricultural surplus can lead to members of a population being allowed to specialize. And increased specialization allows for the manufacture of increasingly complex goods.

For many years I have been wondering what minimum population levels would be necessary to produce and maintain a historical technology level. My thought would be that if a population could produce 90% what was manufactured and commonly available within a specific historical timeframe that would be considered the level they could reproduce. I am not saying that they would need to produce all items just that it would be possible within a year or so. I am assuming access to raw materials, knowledge of the technology, and the basic infrastructure and tools required.

Could an adult population of 250 reproduce most 1790s products from scratch? Could a population of 5000 match the 1850s? The numbers after this point would seem to shoot up in my opinion, as rail lines and the industrial revolution force interdependency, but this is mitigated by increased agricultural efficiency. Considering all that is available in the early 1900s (Cars, airplanes, light bulbs, generators, everything in the sears catalog, etc) a population of at least 250,000 seems reasonable. Cuba's population of 11 million, to me feels like it could produce and maintain a technology of the late 60s if it was isolated.

Of course with tremendous effort a small population could produce i a few items of a vastly higher technological level but I am concerned with the general technology levels.

Does anyone know or any research or discussion on this topic, or does anyone have any opinions they would wish to share. Don't worry if my numbers seem wrong to you, I have wrestled with these numbers for a long time and find myself shifting in both directions all the time.