Post-scarcity/How do we get from here to there?
In a sentence: by increasing the amount and quality of physical goods (through automation) via freely available open-source channels, until it makes no sense for anyone to rely on anything else.
The transition beyond our current institutions to post-scarcity, due to social and political reasons, may though be harder than actually developing the technologies required to support a technological post-scarcity.
However some form of true post-scarcity - perhaps regulated at the personal consumption level unless agreed at a community/regional level for larger projects - where all people on Earth do not have to work for pay, or any kind of exchange, and have a very high standard of living does appear possible on the face of it. The Earth's crust contains quintillions of tonnes of useful elements; energy is plentiful (solar, geothermal, nuclear) and automation of everything significant including the fabrication of other automated systems is likely to be within mankind's capabilities. Open-source design and engineering could be the development model.
Potential routes to transition to post-scarcity
Here are three methods of how, it might be possible to transition from our current economy to a post-scarcity (there may be others of course):
1) Advanced digital fabrication and closed-loop operations on a local scale - think of a very advanced version of Open Source Ecology who are operating at a small farm-scale.
2) Let industry compete to zero-cost (or infinitesimally small cost) through automation. The companies could be helped along by employing some open-source systems in their operations (and even contributing to OS projects) to reduce their costs in non-core areas. With companies in all industries eventually doing this to help them compete, the non-core areas from each industry may eventually all overlap, joining together to provide a complete alternative open-source infrastructure.
3) Intentional duplication of all key infrastructure, manufacturing and services to eventually create a parallel automated open-source economy by open-source advocates - much as was done in the software world, developing C compilers, operating system kernels, graphical desktops, IDEs and key applications. It took a while to get that all in place but eventually it got to a stage where Linux could be a primary OS for developers and geeks (about 10 years), and now it is perfectly usable for normal computer users (after about 20 years).
Power, control and jobs
A common argument is that existing people / companies / systems wouldn't let it happen - but it is simply another form of competition. Incumbents can certainly make things difficult, but they are unlikely to be able to stop it happening altogether. If it is open-source and free (or lower cost than a commercial alternative) then the commercial producers / distributors may have a hard time competing if the goods or services are of a similar quality. You could argue that open-source networks and organisations operating at cost (and driving it towards zero) during the transition period are perhaps the ultimate example of effective market economics at work.
As an example, Microsoft couldn't stop Linux being developed and used globally often in direct competition with their consumer and business software. There is estimated to be around 33 million computers [1] running a Linux-based operating system (including the Android mobile phone OS), and those are just the machines that are browsing the web. This figure probably doesn't include the millions of server computers which run Linux, and is in fact the dominant OS in that sector with about 60% of machines running some flavour of it.
Open-source hardware is still very nascent, but an interesting example in the physical (rather than software) world is the open-source RepRap machine, where it and it's derivatives now make up a majority share of new FDM 3D printers (according to Dr. Adrian Bowyer).
Human progress since the enlightenment has been rapid and continually disruptive to the apparent status-quo. This is still very much the case today, and near-future mass-scale open-source products and services are a continuation of this. The buggy-whip manufacturers will always complain about disruptive change of course, but consumers will be getting greater choice for less and less cost. How jobs will be affected though with advancing automation is another issue altogether.
Interestingly as the average person's earning potential perhaps goes down as automation increases, the more easily and cheaply people will be able to get goods and services from automated open-source systems, so it may balance to a certain degree. One extrapolated end-point is that as people's earning potential gradually falls to zero over time, all significant product and service costs will also be tending towards zero. Another (rather pessimistic) alternative scenario, is that as automation increases, fewer and fewer people are able to afford the products produced by the dominant companies. This seems unlikely as commercial entities wouldn't be able to survive if there were too few customers in that market, so they might as well end up giving things away by the time all significant production is done 100% by machine, because what does it matter if all the companies costs were followinng the same path too? However if the companies didn't do that, it wouldn't matter anyway as the open-source providers would take their place. This seems to be inevitable barring some kind of governmental intervention. None of this would happen overnight so society would have adjust, as it always has done. This is why we don't still live in the stone age.
At a personal level
Imagine a world where you can grow all your own food in a small greenhouse, in a largely automated system. Your water falls freely from the sky or wells up from the earth and is filtered and cleaned automatically. Any time you want a new gizmo, you can find a design online and fabricate it locally or shipped using an efficient automated delivery service. Children have access to the best education ever conceived, for free. You have abundant free energy from the sky and under the ground. What need have to you engage with the monetary economy?
The situation sketched above is not just a vision of the future at all; it is possible now. All these things are already available for free, but few people are aware of it, fewer are doing it and it takes too much work and requires too many compromises. Right now, open-source hardware, what little of it there is yet, is of lower quality than commercial hardware, but it is early days. Manufacturing currently is too labour-intensive, costly and inflexible. Wonderful open educational resources are out there, but are not properly organized into a comprehensive, easy-to-navigate curriculum. And you can grow all your own food, but it's tough work. It is easier, currently, to work for a living and perpetuate the money-system that rather restricts humanity's potential.
The way to bring about a global post-scarcity economy and to make it the only game in town is simply to add to the commonly-held resources of mankind until they become indisputably better than, or as good as, commercial resources. Learn how to grow your own food and give the seeds and the exact method of growing away for free on the Internet. Contribute to open-source educational materials. If you can program, contribute to open-source software projects. If you have any idea about engineering, contribute to open-source hardware projects. Use open resources yourself, note whatever problems you have with them, and correct them or else bring them to the attention of an expert who can correct them. Bring open projects to the attention of architects, researchers, engineers and programmers. Print fliers about an open-source project like Fab Labs and RepLab and drop them in university engineering lecture halls. Get involved in open-source robotics and very practical hands-on projects like those being developed by the Open Source Ecology team. If you know about a lot about chemistry or Egyptian history or flamingoes, improve Wikipedia or open educational material. If you can sew and make clothes, post sewing patterns online. Focus on quality. You don't have to do all the contribution yourself; get your friends to help. Even get your acquaintances to help. Connect those with design skill to those with design projects. Study whatever you're passionate about and think how you can use it to add value to all mankind.
By adding to this pool of resources, you make it easier for people to build their own abundance. And the easier it becomes to live a life of abundance and leisure without any need for the monetary economy, the more people will do it. Thousands of people have dropped out of the monetary economy onto organic farms, but that simple, pastoral lifestyle is not to everyone's taste. Post-scarcity will not come about until it is possible to a high standard of living without having to rely on the current economic system.
Lead by example. Use the information available to you to find a solution to your needs of water and energy and food and shelter. Once you have solved your basic needs without reliance on the monetary system, move it up a notch and solve your wants of clothes and furniture and electronics without reliance on the monetary system. And always contribute, contribute. Of course, like some strange tribe, you will need to come to an agreement to trade with the civilized men around you and co-exist with them. You will need money at first, but as you work things out you will become more and more independent, more and more resilient. And keep contributing, contributing, making it easier for others to follow your trail. Don't do all this alone; do it with your friends. It's much more fun that way.
Social change doesn't come by decree from the politicians' halls. It always comes from the bottom up, from the young vibrant minds who see clearly and say, "I can see a better way to do things".
Many grass-roots and open-source type projects are making a real difference in the world right now, so join an existing one or inspire others and start your own.
The universal commons is the store of information freely available to mankind. It is all about information, and information-management is now the key determinant of success in food production and medical care — and digital manufacturing will make information the only non-trivial ingredient in physical goods. This trend towards information-rich activities is important because information is so often free and importantly is non zero-sum, meaning that I can give it to you without diminishing my own supply. If information determines the production of other resources, and that information is free along with abundant material and energy, then global abundance will be possible. The key enabling factors are an effective means of turning Virtual designs into physical objects and universal access to information — and both of these are expected to improve by several orders of magnitude over the course of the next few decades.