A few comments on the ‘Culture’….The origins of the interstellar civilization, as stated by the author of the novels, occurred when an unspecified number of autonomous star ships and artificial habitats began to federate with a (small?) number of Artificial Intelligences and a much smaller number of planetary based polities. In the period the novels are set, many Culture citizens (this mainly refers to the (post-) human population but not exclusively) live aboard so-called ‘Rocks’, habitable, space-faring asteroids. This number presumably makes up a significant proportion (10% of all humans, drones etc) of the Culture’s population that live at any one time aboard their interstellar craft. It is safe to assume that these people are the descendants of the Culture’s founders. Most of the (human) population, however, live on artificial worldlets called ‘Orbitals’.

Overpopulation could explain the reason for the construction of the first Orbitals but this would soon be sated after the construction of the first dozen or so when the Culture has thousands with varying populations (the number actually living on planets is anyway dwarfed by the number living aboard Rocks and star ships). Invasion by a hegemonic power doesn’t seem a likely reason for people to move to a fixed location when their home already has the capacity to both defend itself and escape, although an Orbital would be easier to defend than a planet. From comments suggesting that at some point in the Culture’s history many or all of its human citizens were living in virtual space gives another explanation for the need to construct Orbitals. The concept of virtual immortality, uploaded personalities and technological reincarnation coinciding with the development of Artificial Intelligence is a recurring theme. Another is the vast number of apparently human civilizations, at varying stages of development, existing in the Galaxy, all of whom outnumber the Culture in terms of population numbers. Intelligence and intelligent life of all kinds is valued by the Culture. It is very likely that there are many cases where a civilization has undergone a planetary catastrophe, killing off most of its living population but leaving intact the uploaded ‘souls’ of many of its citizens. There would be other cases where ‘AI Constructs’ of scientists and explorers are uploaded into an interstellar probe instead of a living crew or a ships AI joins the Culture along with any living or virtual crew. Similarly, either situation could occur during a mass Sublimation of the civilization in question.

For various reasons, the Culture may want to rescue/ resurrect these individuals and upload them into new bodies, who would probably want to live on the kind of planetary environment which Orbitals simulate. With no immediate population pressure and an abundance of planetary debris in solar systems, there is time to build thousands of Orbitals while the new Culture citizens are ‘resurrected’ (and yes, this does sound grotesque but would surely be done on a voluntary basis. Besides, the Culture would consider these individuals to be alive). Population growth on a single planet would eventually be limited, but the number of total ‘uploads’ could continue to the tens or even hundreds of billions on some planets. There is the distinct possibility of individuals being ‘twinned’ due to multiple uploads- an individual could have themselves uploaded for/ before a military or deep space mission and their ‘copy’ goes missing. Meanwhile, the original personality is uploaded just before physical death. Years later, both ‘twins’ are resurrected by the Culture, presenting major philosophical headaches for years to come! From this it is easy to see how high a ‘virtual’ population could get!

An Orbital is completed over several stages which involve the construction of several artificial continental plates until the Orbital is completed. When one plate is safe it can then be settled while the others are still under construction. It is likely that several Orbitals would begin to be constructed at the same time. If the ‘resurrectees’ all return in young fit bodies, and have the ability to switch gender, the population could easily increase by an order of magnitude before it stabilizes and matures over its first couple of centuries. Over time, an Orbital would be settled by other Culture citizens and beings from other civilizations.

http://groups.google.com/group/rec.arts.sf.written/msg/2b05e32641fee4c2?hl=en&

From the sourced article, it is relatively easy to see the internal economies of the various Rocks and other habitations as being some kind of voluntary collectivism/ socialism. Respect and concern for one’s immediate environment would increase in an individual in the absence of market dynamics and especially if the survival of one’s personality can be guaranteed after the body’s physical death effectively by one’s environment.

Aboard a General Systems Vehicle, every physical need is provided by the ship. There is little opportunity for a real economy to develop but group activities are common.

‘Aboard’ an Orbital one’s needs in terms of sustenance, housing, protection and medical support can be provided so cheaply in terms of energy and matter they are provided for free. This leaves the opportunity for a voluntary or a market economy to develop in terms of non-essential wants.

As a further comment, it would appear that there is/ may be some ‘fictional conflict’ between Star Trek TNG since the publication of “Consider Phlebas”. The ‘Borg’ are very much an evil pastiche of the Culture, a statement of loss of individuality in a space-based anti-civilization where collectivism has gone too far! ‘Section 31’, introduced in “Deep Space Nine” and apparently as old as the Federation itself, is a mirror to the Culture’s own ‘Special Circumstances’; both use any and all means to achieve their objectives. Their recruitment of ‘Doctor Bashir’ by ‘31’ is a similar story to many individuals in the ‘Culture’ novels (especially “Excession”) who find themselves carrying out jobs for ‘Contact’ or ‘Special Circumstances’ without being sure which organization they are working for or what their membership status is exactly.