I do not agree on what the shift from slavery to feudalism meant in the west roman parts of Europe (in the east roman the roman empire lived on much longer, but "fall of rome" is usually a referal to the fall of the western realm). The feudal system was not more efficient in terms of food production and food security. From 200 AD to 600 AD the (non-USSR) Europe suffered a population decline from 44 millions to 22 (according to Livi-Bacci - A concise history of world population).

I think the description of slavery economics misses some points. This is how I see it. As the Roman empire expanded there was a conflict of ownership of the newly aquired productive resources (land and the slaves to use it) between the really wealthy families - lets call them the senatorial class - and the free (but not wealthy) common person. The legioners of rome were commoners.

As long as the empire expanded both the rich and the commoners could get a part of the new resources. The wealthy got richer and the legioners got land as pensions. Eventually the Roman Empire reached its natural limits, Sahara in the south, low productive forests and marches in the north, the Atlantic in the East and was limited by a to strong opponent - the Parthian empire - in the east.

Without means to expand the wealthy started to expand their power - most notably their landholdings - at the expense of the commoners. As the senatorial class was not taxed this was an uneven fight that became more uneven over time. As more land became pert of the senatorial class latifundias, fewer free peasants remained to be taxed, and thus had to be taxed harder. To prevent peasants from fleeing their land, they were bound to it. Thus serfdom was introduced. As central power weakened, the empire lost cohesion. The germanic tribes took over what was already a system gone feudal. And slaves were still around.

If the system was doomed to collapse or not is a question of perspective. On one hand it is quite obvious what needed to be done, taxing the senatorial class, breaking up too large latifundias and so on. On the other the emperors came out of the senatorial class and had little reason to do so. The risk with opposing the senatorial class was obvious - beware the ides of march!

Today we have a similar problem as we are passing the peak in global resource extraktion. The über-wealthy and their immortal multinationals avoids taxes and attempts to break up monopolies (Microsoft is the prime example, but there has been others). That this weakens the governments and will worsen the decline for the great unwashed masses seems to be of little concern.

P2P is the most hopeful factor in getting a softer landing. The shift is however fought tooths and nails by the present structures. The p2p culture production is already often illegal, even if non-commercial. And it is growing, in one of the early drafts IPRED 2 included making patent violations a crime punishable by jailtime. Microsoft claims that Linux violates at least 200 of their patents. Since you can patent almost anything these days (especially in the US), they are probably right.

Guess what I am saying is that p2p society can come, would be good, but is not given. And the other scenario is the neo-feudalism. Multinationals keep on growning, states keep loosing power. Independent use of means of production - even your own ideas - is outlawed and policed by the multis. Social protection, even physical protection becomes the domain of multis. Gradually the systems break down as the multis can no longer leach on the states but becomes the states - highly feudal ones.

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se